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  • Annonser

Attenborough’s climate film: more fiction than facts

 

[Denna text på svenska.]
David Attenborough’s film ”Climate change – the facts”, is now being shown in many countries. Swedish Television recently aired it. Unfortunately, it is a film that, with its imagery and its rhetoric, is very much like such repulsive and distasteful propaganda films that one thought we would be spared in our present-day knowledge society.

One could expect that those who are now convinced that we are approaching a climate disaster, at least should convey their message objectively and without affect. But Attenborough’s film is probably the most misleading and bombastic I’ve seen since Al Gore’s 2006 film ”An Inconvenient Truth”.

The worst may not be the individual errors and half-truths; the worst is that Attenborough (and the other contributors) give the impression that everything is certain (”evidence is now unequivocal”), that all researchers agree and that there is nothing to discuss or add. Now action is required.

But this is not true. Researchers connected to the UN Panel on Climate Change (IPCC) also have different judgments. Some such points are described here [in Google translation from Swedish] (about sea levels and how much time we have left to act) and here (about the so-called hiatus of global warming in recent years) and here (about the medieval warm period).

 

greatest threat in thousands of years

Are we really facing ”our greatest threat in thousands of years”, worse than thousands of years of war, famine, pandemics and purges?

 

The film starts with a few voices from various news programs reporting extreme weather and heat, then Attenborough is heard as a voiceover to a series of short video clips:

Right now we are facing our greatest threat in thousands of years [photos of white smoke from factory chimneys are shown, in one chimney the emitted gas is burning] – climate change! [Lightning, hard rain and rain curtains moving across a landscape.]

Naomi Oreskes (historian of science, Harvard University): For a long time climate change was considered something that scientists predicted would happen in the future [image of a ticking clockwork, a big ocean wave, dramatic music] but that’s no longer the case.

Richard Lazarus (professor of environmental law at Harvard University): What we’re doing right now [image of a truck overturning in a hurricane wind on a bridge, and then almost sliding off the roadway] is we’re so rapidly changing the climate, for the first time in the world’s history people can see the impact of climate change. [The sound of glass shattering, pictures of buildings destroyed in a hurricane, flooding.]

Mark Maslin (professor of climatology at University College, London): Greater storms, greater floods, greater heatwaves, extreme sealevel rise.

Michael Mann (climatologist at Pennsylvania State University): All of this is happening [pictures of melting and floating snow and ice] far faster than any of us thought possible [pictures of ice blocks on rocks, washed over by water and almost disappearing].

Already the first sentence proclaiming ”our greatest threat in thousands of years” is most probably a huge exaggeration. Not even the IPCC paints a picture of an impending disaster that would be worse than World War II or the Great Plague, for example.

 

lastbilen_på_bron

”For the first time in the world’s history people can see the impact of climate change,” says professor Richard Lazarus in the film, and this is illustrated by pictures of a large truck in a storm, which slides off the roadway on a bridge.

 

One cannot see climate change, as Lazarus claims. And later in the film Michael Mann states: ”We are seeing the impacts of climate change now, play out in real time.” Singular weather events could possibly, in retrospect, be put into such a context, but hardly while they are going on. Only 20-25 years ago, experts believed that climate change could not be detected from data from just a couple of summers or winters; observations were required for perhaps a hundred or several hundreds of years. This has now shrunk to 30 years. But it has hardly shrunk so that you can see it in the present.

Storms and floods

The claim of storms and floods getting more severe, worse heat waves and extreme sea level rise has not been supported by research. The IPCC has not seen an increase of cyclones over the past hundred years: ”Current data sets indicate no significant observed trends in global tropical cyclone frequency over the past century…” (Fifth assessment report 2013/14, chapter 2, p. 216).

In the special report from IPCC 2018 (Global Warming of 1.5 °C), it is claimed that at least the number of cyclones (in contrast to their force) will decrease with warming above 1.5 degrees: ”the total number of tropical cyclones is projected to decrease during global warming” (p. 204). Much is written about what will happen if we get ”intensified storms”: disturbed ecosystems, increased difficulty for people to recover from storms, damage to forests and corals, etc. That’s if. But will storms really be more plentiful and/or stronger? The Special Report’s view on this is not altogether clear.

In the case of floods, the Fifth assessment report had not seen trends indicating more frequent or worse floods: ”There continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale over the instrumental record.” (Fifth assessment report 2013/14, ”Technical summary” p. 112). However, the special report from 2018 claimed that some increased risk could be expected regionally (future risk, few actual observations have been made), but they also pointed out: ”There are studies, however, that indicate that socio-economic conditions will exacerbate flood impacts more than global climate change … ”(The Special Report, p. 214).

NASA has found that sea levels rise about 3 millimeters per year, since at least the 1990s. This is hardly the extreme sea level rise being proclaimed of a up to one meter to the year 2100, which is said in the 37th minute of the film. If one wants to scare people with dramatic climate changes, it is of course important to make weather events that happen today appear as if they are unprecedented in history. This is often said about temperatures, forest fires, etc. In Attenborough’s film, astrophysicist Jim Hansen says that sea levels previously have ”been stable for several thousand years” (in the 18th minute of the film). But it’s just the opposite. The sea level has both dropped and risen for thousands of years. The situation has also been affected by a land rise since the ice from the last ice age withdrew.

 

a man made disaster on a global scale

Attenborough talks about ”a man made disaster on a global scale”. His view of nature fits into a tradition of ecologists and natural philosophers who regard nature as having been rather static, until man broke the balance.

 

After the initial striking clips, Attenborough appears in a beautiful English landscape and says: ”Standing here in the English countryside, it may not seem obvious, but we are facing a man made disaster, on a global scale. In the twenty years since I first started talking about the impact of climate change on our world, conditions have changed far faster than I imagined. ”

Attenborough’s view of humans as a species that both destroys itself and the earth fits into a tradition of ecologists and natural philosophers, e.g. George Perkins Marsh or Ernst Haeckel, who regarded nature as fairly static and well balanced, as a perfect machine – until man came and ruined everything.

Entomologist and ecologist Stephen A. Forbes wrote in his article ”The Lake as a Microcosm” (1887): ”Perhaps no phenomenon of life in such a situation is more remarkable than the steady balance of organic nature, which holds each species within the limits of a uniform average number, year after year … ” and further on that ”Although every species has to fight its way, inch by inch, from egg to maturity, yet no species is exterminated, but each is maintained at a regular average number which we shall find good reason to believe is the greatest for which there is, year after year, a sufficient supply of food.” Such a view of nature hardly leaves room for any Darwinian natural selection.

Ecologist Daniel Botkin, on the other hand, says that change has been the rule in the history of the earth, and that includes climate change:

None of these steady-state assumptions are true. Species do not come into instant equilibrium with a new climate; they are always in the process of responding to previous environmental change. There are other factors that limit distribution that are changing over time. Individuals, populations, species have the ability to adjust to a changing environment; otherwise they all would have gone extinct in the past. (Botkin, The Moon in the Nautilus Shell , 2012, p. xiii.)

The Attenborough film then shows an animated world map, in which colors indicate temperature changes between 1884-2018. At first, the map is yellow, white and blue, then blue and orange, then light red, and finally, in the 2000s, it becomes dark red, as if the earth is glowing: ”Our climate is changing because of one simple fact, our world is getting hotter,” says Attenborough.

The difference in temperature between this blue-white cold world of 1884 and our red-hot earth 2018 is about 1 degree Celsius! Since this is a question of mean temperature, one should note that this implies that the earth has become say three or four degrees colder in some places and say three or four degrees warmer in others. That’s what the different colored spots show. Whether this is good or bad depends on the local conditions.

The temperature rise: cause and consequences

Even some of the scientists within the IPCC network are aware that the effects of a possible future temperature rise must be assessed differently at different locations. Mike Hulme, now a professor of human geography at Cambridge University, wrote this (February 5, 2002) in one of the emails that later leaked to the public in the so-called Climategate scandal: ”… the panel text [the discussion then concerned IPCC’s Fourth assessment report/KET] does not mention that some people (and countries) may experience benefits as a result of climate change”. (The whole email is here.)

Peter Stott (at the UK Meteorological Office and Exeter University) then says: ”What we’ve seen is this steady and unremitting temperature trend [again the image of the map glowing], twenty of the warmest years on record have all occured in the last 22 years.”

 

rolling_stoneaug_2019_hottest

Sometimes you get it a tad wrong. ”Human history” is something else than ”recorded history”. And ”recorded history” is something different than ”historical temperature records”.

 

You frequently hear proclamations that various summer months certain years were the hottest since measuring started (sometimes they even were the hottest in human history). Most recently, it was July 2019 that was declared the warmest since measuring began.

One must ask, what is meant by the hottest month? Is it the highest average temperature for the whole month? Or is it a month that has had a peak temperature a certain day or week? And are we talking about anomalies (deviations from the ”normal” or average temperature over a longer period at a certain location) or absolute temperature (what the thermometer actually shows)?

When NASA declared 2014 to be the warmest year measured (since 1880), they forgot to mention that the difference with 2010, previously considered as the warmest year, was 0.02 °C. The error margin was said to be 0.1 °C. Thus, the margin of error was 5 times greater than the measured (calculated) difference. Furthermore, the compilation of measurement point data from all over the earth is so uncertain that the announcement that 2014 was the warmest year since 1880, was probably certain only to 38 percent. (See article ”Nasa climate scientists: We said 2014 was the warmest year on record … but we’re only 38% sure we were right” in Mail Online, January 18, 2015; maybe here too)

It is being discussed whether we for twenty years now have experienced a pause in global warming, a so-called hiatus. See ”Has global warming stopped?” (in Swedish, with Google translation here). But how can there be a hiatus (if that is the case) and record heat at the same time?

The answer is probably that the warming that has been discussed in recent years is so small, it is tenths and a hundredths of a degree, that it can also be seen as a decrease in the heating that was much more tangible during the years 1920-40 and 1980-98. As for the years 2010 and 2014, the margin of error is so large (and the difference so small) that the relation could be the opposite: that 2010 was warmer than 2014.

Peter Stott also says: ”What is striking is that this warming trend cannot be explained by natural factors, it is caused by human activities, in particular by use of fossil fuels.”

Why couldn’t natural influence be the explanation? After all, warm periods have existed for thousands of years before both industrialism and before man. There have probably been warm periods, with no particularly high carbon dioxide content in the atmosphere, and also quite cool periods, when the carbon dioxide content was relatively high (according to Ernst-Georg Beck 2007, the CO2 concentration around 1820-30 may have been higher than now). So the correlation is not ascertained, at least not regarding carbon dioxide as the main regulator of average temperatures over longer periods of time. Historically, solar activity, volcanoes, the inclination of the earth’s axis, ocean currents, etc. would (also) have had an influence.

It should be pointed out that although most people, including so-called skeptics, agree that the earth has become somewhat warmer over the last hundred years, and that carbon dioxide probably has a (greater or lesser) role in this, there are still great uncertainties. The number of measuring points on the earth for temperature is not very big. GISS/NASA now lists 7,300 weather stations, but that includes closed stations whose data is used in historical statistics and graphs. In practice, data from perhaps around 2,000 stations are used today. Especially over the world ocean, the picture is extremely incomplete. How data from this uneven coverage may be compiled and calculated into a ”global average” is very complicated and extremely uncertain.

Recently, some evidence has also been presented about unreliability of the HadCrut4 database, on which many temperature calculations are based. The database may be suffering from major errors. In his doctoral dissertation from 2017, John McLean, at James Cook University in Townsville, Australia, points out around 70 problems with these temperature data, e.g. that some corrections, that must always be made of measurement data, also create a false notion of heating. (See McLean, An Audit of Uncertainties in the HadCRUT4 temperature anomaly dataset plus the investigation of three other contemporary climate issues, diss., James Cook University, 2017.) Also in this case, there is thus reason for a TV program claiming to tell the facts, to mention the uncertainties that exist.

The IPCC often states that there is evidence for one thing or the other based both on observations and on computer-generated climate models. But these models require verification – so they cannot easily be included in the evidence. The Special Report from 2018 states, for example, on page 183: ”Evidence for the assessment of climate change at 1.5 °C versus 2 °C can be drawn from both observations and model projections.”

In the ninth minute of the film, Attenborough shows dead bats (or rather so-called flying foxes) in Australia. Despite being evolutionarily adapted to high temperatures, they have succumbed to heat in thousands. You see a moving picture of a little baby bat clinging to his dead mother. Peter Stott says: ”It’s inconceivable that you would see these temperatures without the fact of climate change.”

Then, several dead flying foxes are being put in a wheelbarrow, and you hear someone off camera say ”it’s climate change in action” (at 10:27-10:30). Or rather, you heard it in the original BBC program from April 2019, but this phrase has now been removed in the version shown on Swedish Television. I doubt that Swedish TV deleted this. My guess is that the BBC received criticism for the statement and removed it.

 

climatechangeinaction_svenska

”If you have two more events like we had, the species are gone,” says a female voice, and then a male voice is heard saying ”it’s climate change in action” – but only in the original film from April. In the version that is now shown in Sweden, the last statement has been removed.

 

It has long been known that flying foxes die in this way. In fact, the phenomenon was documented as early as in the 18th century. This is what British naval officer Watkin Tench wrote in a travelogue about his 1790 visit to the Sydney region, more specifically Rose Hill, where it was 40-41 degrees in December:

An immense flight of bats driven before the wind, covered all the trees around the settlement, whence they every moment dropped dead or in a dying state, unable longer to endure the burning state of the atmosphere. Nor did the ‘perroquettes’, though tropical birds, bear it better. The ground was strewn with them in the same condition as the bats. (Watkin Tench, A Complete Account of The Settlement at Port Jackson, chapter XVII, 1793.)

In addition, another program about flying foxes, ”Secrets of Wild Australia” part 4 (made in 2016), was recently shown in Sweden. Here too, it was shown how many bats died because of the heat, but not one word about climate change.

Have forest fires increased globally?

The film then displays extremely dramatic pictures of fires, seen from inside a car and from a house, where flames strike out from all windows in a violent fire. Attenborough: ”Last year saw record breaking wildfires take hold across the globe.” Michael Mann: ”We’ve seen wildfires break out in Greece, even in the Arctic.” (Wildfires in cold areas, such as the Arctic, are not uncommon, as long as the flammable material is dry enough and some kind of ignition occurs.) Mann again: ”We’ve seen a tripling of the extent of wildfires in the western US, in California.” Pictures from a car that drive on a road, where the forest burns on both sides. A shocked father and son who escaped are interviewed about how close they were to death.

The description of the forest fire and the other fires may be correct, but does this really have to do with climate change? According to the statistics, the fires have rather decreased (see, for example, the statistics at NIFC), but it is debated whether they may have become fewer but larger. A program that sets out to report facts should tell if things are contentious. Both in Sweden and the United States, many areas also burned in the late 1800s and 1930s, for example.

In the article ”Global trends in wildfire and its impacts”, published by the British Royal Society 2016, Stefan H. Doerr and Cristina Santín write: ”… global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago.”

In the 16th minute, Attenborough says: ”I won’t say that all can be due to climate change. Last years extreme weather events meant that millions of people needed humanitarian aid.” What does he wish to imply by saying this? That a flood in Kerala in India, of which images are being shown here, may not be due to climate change, but this kind of imagery will be common when floods occur that really are caused by climate change?

This seems to be the film’s main rhetorical device. Everything that is shown, forest fires, floods and dead flying foxes, regardless of what caused the events in question, are examples of dramatic climate change and that it already is underway. And that everything will get worse.

Is the ice melt in the Arctic unique?

The film then moves on to ice melting in the Arctic and Antarctic. Andrew Shepherd (climate scientist, University of Leeds):

In the last year we have had a global assessment of ice losses from Antarctica, from Greenland, and they tell us that things are worse than we expected. The Greenland ice sheet is melting, it’s lost two trillion tons of ice, it’s losing five times as much ice today as it lost 25 years ago.

Here, the program makers, if they wanted to convey the facts, should have mentioned that the masses of ice in both the Arctic and Antarctic always have increased and decreased over the centuries. How the present trend towards ever-smaller summer ice in the Arctic should be interpreted is a controversial issue. Animations showing the Arctic ice maximum during the winter of 1979-2006 can be seen here, and the Arctic ice minimum in the summer during the same time can be found here.

The Arctic also underwent an unusual warming in 1920-40, which the scientists could not explain. Within the framework of their research at the Max-Planck Institute in Hamburg, professor Lennart Bengtsson et al. wrote in 2003:

The Arctic 1920-1940 warming is one of the most puzzling climate anomalies of the 20th century. Over a period of some fifteen years the Arctic warmed by 1.7 °C and remained warm for more than a decade. This is a warming in the region comparable in magnitude what is to be expected as a consequence of anthropogenic climate change in the next several decades. (Bengtsson et al., ”The early century warming in the Arctic: A possible mechanism”, MPI Report 345, 2003.)

The fact that this happened during a period when the increase in atmospheric carbon dioxide was only about 20 percent of today’s, led the scientists to believe that the cause rather was increased solar activity than human influence.

A Danish study from 2005 by Knud Lassen and Peter Thejll examined sea ice in eastern Greenland between the years 1500 and 2000, based on previous surveys of eg. oxygen isotopes in ice cores. Lassen and Thejll found an ice minimum, perhaps as that of today, in the 16th century and significant peaks some time each century from 1600 to 1900. An abrupt decline of ice also happened in the 1920s, as in our days. The variations, they believe, are due to, among other things, solar activity. Finally, Lassen and Thejll write:

The considerations of the impact of natural sources of variability on arctic ice extent are of relevance for concerns that the current withdrawal of ice may entirely be due to human activity. Apparently, a considerable fraction of the current withdrawal could be a natural occurrence. (Lassen & Thejll, ”Multi-decadal variation of the East Greenland Sea-Ice Extent: AD 1500-2000”, Scientific Report 05-02, Danish Meteorological Institute, 2005.)

A 2017 study by Paola Moffa-Sánchez and Ian Hall (”North Atlantic variability and its links to European climate over the last 3000 years”, Nature Communications volume 8, 2017) investigates Arctic ice for 3,000 years using pollen in sea sediment. According to this study, the ice would have covered smaller areas 500 years ago than today. But there are other studies that arrive at other results, so the matter is, as I said, debated, which the TV program should have mentioned.

Sea level rise and coral reefs

The film then turns to sea level rise: ”Rising seas are displacing hundreds of thousands of people,” Attenborough says. You can see pictures of flooded areas, with people sitting on meter-sized small banks with water all around. Colette Pichon Battle (CEO of the Gulf Coast Center for Law & Policy in Louisiana) says: ”In the United States Louisiana is on the frontline of this climate crisis, it’s loosing land at one of the fastest rates on the planet. A rate of a football field every 45 minutes.”

Louisiana has an extremely large land loss, which is largely due to that the land sinks and has been doing so for at least a hundred years. A global sea level rise of 3 mm per year (average) and a local landfall of 6 mm gives a total sea level rise of 9 mm per year. It has little to do with climate change, but to a certain extent it has to do with human impact. Badly designed hydraulic engineering, as well as the drawing of oil and gas pipelines in the lands around the Mississippi River have affected erosion. Colette Pichon Battle says that the residents of the Isle de Jean Charles, in the lowlands just off the coast of Louisiana, have been called the first climate refugees in the United States. That is hardly the case. The land loss in Isle de Jean Charles has been going on for at least a hundred years.

In the film’s 23rd minute, Attenborough says that a third of the world’s coral reefs have bleached and died in the past three years due to heat stress. This does not seem to agree with several articles on how the coral reefs recover, e.g. Michael D. Fox et al., ”Limited coral mortality following acute thermal stress and widespread bleaching on Palmyra Atoll, Central Pacific,” described here.

A Chinese study even assumes that the corals are well off in the heat: ”We identify abrupt coral reef recovery in the northern South China Sea (SCS) since the last century (especially post-1960 CE), indicating that the Current Warm Period is an optimal episode for reef growth in the northern SCS.” (Shuang Yan et al., ”Episodic Reef Growth in the Northern South China Sea linked to Warm Climate During the Past 7,000 Years: Potential for Future Coral Refugia”, JGR Biogeosciences, April 2019.) Again, the film should at least have mentioned that the issue is debated.

In the 26th and 27th minutes of the film, a few so-called climate deniers appear, e.g. Paul Broun, who says that no temperature rise has occurred in eight years. This is apparently considered so stupid that it doesn’t even deserve a comment. Perhaps Broun was out a bit early to say this in 2001, but the ”warming pause” is something that is being discussed – even by the IPCC (see ”Has global warming stopped?”; in Swedish, with Google translation here). No significant temperature rise has occurred (except for the natural fluctuations caused by the El Niño phenomenon) in 20 years (1998-2018).

Lord Lawson is also presented as a ”denier” when he says that there are also ”huge benefits from a warming planet”. This too is obviously regarded as so stupid that it doesn’t require any comment. Formerly chilly areas of the earth will likely be cultivated easier. The earth’s vegetation also benefits from increased carbon dioxide, deserts and other arid areas have begun to green. However, this is not primarily related to the heat but is due to the fact that carbon dioxide acts as a kind of fertilizer for plants. Lu, Wang & McCabe found ”extensive areas of ‘greening’ in dryland areas of the Mediterranean, the Sahel, the Middle East and Northern China, as well as greening trends in Mongolia and South America.” (”Elevated CO2 as a driver of global dryland greening”, Nature Scientific Reports, February 2016.)

See also this web page at NASA, where it is said that between 25 and 50 percent of the Earth’s green areas have become even greener.

In the 30th minute of the film, however, professor Matthew Hansen at the University of Maryland mentions the opposite phenomenon, deforestation. He shows a map, where forests disappear on large areas of the earth (according to the map, most of Sweden and Finland appear to have had their forests burned or felled, which is very strange – to put it mildly).

Apart from the matter of size of the affected regions, the question is whether this is a climate issue or a felling issue. Hansen says that rainforests are burned down and replaced with crops of soybeans or rubber or used as pasture for livestock. But among that which affects most, he says, is the cultivation of oil palms. Palm oil is found in almost everything, adds Mark Maslin, professor of climatology at University College, London. However, no one mentions that palm oil is used as ”environmentally friendly” biofuel.

Permafrost

Attenborough says (in the 38th minute) that in addition to all this, we could be threatened by even worse disasters, called tipping points, i.e. that any process reaches a point where it becomes irreversible. However, in its assessment of 2013/14, the IPCC has discarded most of these concerns. Some problems may arise from melting permafrost, that can emit greenhouse gases. See ”Is the climate apocalypse canceled?” (in Swedish, Google translation here).

When Attenborough then describes the problem with the permafrost, it is misleading. He mentions that methane (a greenhouse gas 20-30 times more potent than carbon dioxide) is found underground in the permafrost. You can then see ecologist Katey Walter Anthony from the University of Alaska step out on the ice on an ordinary lake near Fairbanks, Alaska. But there is a difference between methane in ordinary lakes, that are emitted constantly, and methane that can be formed and released from permafrost if it melts.

Dr. Anthony shows that there are bubbles frozen in the sea ice, and with a little hot water she melts the top layer. The gas bubbles come out into the air and they light a match so that the gas bursts into flames. The impression is spectacular, of course. The problem with methane, however, is not that it burns, but that it more efficiently than CO2 blocks the earth’s heat radiation from disappearing into space.

No one knows how much methane the permafrost (which is mainly found in the northern hemisphere) contains, but estimates are of 1.7 trillion tonnes of carbon, bound in organic material, which can thus become both carbon dioxide and methane when and if the permafrost begins to melt and the organic material degrades. It is estimated that current warming could result in 1 gigaton of methane having been emitted from thawing permafrost by the year 2100. By comparison, lakes, marshes and other wetlands are a greater source of methane, 0.167 gigatons per year, which by the year 2100 would be 13.36 gigatons.

On her website, Dr. Anthony shows a not-so-ominous side of the methane bubbles. She and her colleagues are working on a project that will provide villages in northern Alaska with cooking and heating gas from the sea bubbles instead of from imported diesel.

The IPCC 2018 Special Report (p. 208) refers to a study in which it is believed that it might be possible to bind methane and carbon dioxide in permafrost to increased peat formation: ”Transient releases of CO2 and CH4 may follow permafrost melting, but these occurrences may be compensated by peat growth over longer time scales (Yu et al., 2010).”

Both solar and wind power are mentioned as alternatives to the fossil fuels. Nothing wrong with that, but a program that wants to convey ”the facts” should also mention some of the problems with these energy sources. First of all, they have an uneven energy production and can hardly be an alternative for developing countries that want to build up heavy industry.

One problem with solar panels (if one is afraid of carbon dioxide) is that they are currently being produced in countries where electricity is produced using fossil fuels (China, for example). The solar panels often require huge landscape areas, thus interfering with habitat and wildlife, for instance are birds being injured. They also require large amounts of water, e.g. for cleaning, and when they have served out, they create environmentally hazardous waste. Wind turbine propellers kill numerous birds, insects and bats, animals usually regarded as important to protect for the sake of biological diversity.

It is sad, not to say devastating to public opinion, to public interest and to climate policy, that the media hardly ever report on the diversity of climate research, but constantly state that all scientists agree that a global disaster is rapidly approaching. I have tried to show here, that there are other sides to these matters, that mustn’t be excluded from the public debate. I find it highly counterproductive for education and sensible decision making to produce alarmist films like this.

Annonser

Attenboroughs klimatfilm: mer fiktion än fakta

 

[This text in English.]
Nu visar SvT David Attenboroughs film ”Climate change – the facts”, som på svenska fått titeln ”Klimatkrisen”. Det är tyvärr en film som med sitt bildspråk och sin retorik för tanken till sådana obehagliga och osakliga propagandafilmer som man trodde sig förskonad ifrån i vår tids s.k. kunskapssamhälle.

Man tycker att de som nu är övertygade om att vi närmar oss en klimatkatastrof åtminstone borde föra fram sitt budskap sakligt. Men Attenboroughs film är nog det mest vilseledande och bombastiska jag sett sedan Al Gores film ”An inconvenient truth” 2006.

Det värsta är kanske inte de enskilda felen och halvsanningarna; det värsta är att Attenborough (och de andra medverkande) vill ge intryck av att allt är bevisat (”the evidence is now unequivocal”), forskarna är eniga och inget finns att diskutera eller tillägga. Nu krävs handling.

Men det stämmer inte. Även forskare anknutna till FN:s klimatpanel (IPCC) har olika bedömningar. Några sådana punkter framgår t.ex. här (om havsnivåerna och om hur lång tid vi har på oss) och här (om den s.k. pausen i uppvärmningen de senaste åren) och här (om bl.a. den medeltida värmeperioden).

greatest threat in thousands of years

Står vi verkligen inför ett hot, och är det i så fall värre än tusentals år av krig, svält, pandemier och utrensningar?

Filmen inleds med några röster ur olika nyhetsprogram om extremt väder och hetta, därefter hörs Attenboroughs röst som s.k. voiceover till en rad korta bildklipp:

Right now we are facing our greatest threat in thousands of years [bl.a. bilder på vit rök ur fabriksskorsstenar, i en skorsten brinner det som släpps ut] – climate change! [Blixtknall, hårda regnskyar förflyttar sig över ett landskap.]

Naomi Oreskes (vetenskapshistoriker, Harvard University): For a long time climate change was considered something that scientists predicted that would happen in the future [bild på ett urverk som tickar, stor havsvåg, dramatisk musik] but that’s no longer the case.

Richard Lazarus (professor i miljörätt vid Harvard University): What we’re doing right now [bild på lastbil som välter i orkanvinden på en bro och sedan nästan glider av vägbanan] is we’re so rapidly changing the climate, for the first time in the world’s history people can see the impact of climate change. [Ljudet av glas som splittras, bilder på byggnader som förstörs i en orkan, översvämning.]

Mark Maslin (professor i klimatologi vid University College, London): Greater storms, greater floods, greater heatwaves, extreme sealevel rise.

Michael Mann (klimatolog vid Pennsylvania State University): All of this is happening [bilder på smältande och flytande snö och is] far faster than any of us thought possible [bilder på isblock på stenar som sköljs över av vatten och nästan försvinner].

Redan första meningen om ”our greatest threat in thousands of years” torde vara en enorm överdrift. Inte ens FN:s klimatpanel målar upp en bild av en annalkande katastrof som skulle vara värre än andra världskriget eller digerdöden t.ex.

lastbilen_på_bron

”For the first time in the world’s history people can see the impact of climate change”, säger professor Richard Lazarus i filmen, och det illustreras med bilder på en stor lastbil i storm, som kanar av vägbanan på en bro.

Man kan inte se klimatförändringar, som Lazarus påstår. Michael Mann säger också senare i programmet: ”We are seeing the impacts of climate change now, play out in real time.” Enstaka väderhändelser kan kanske i retrospekt sättas in i ett sådant sammanhang, men knappast medan de pågår. För bara 20–25 år sedan menade många forskare att klimatförändringar kunde man inte se på några somrar eller vintrar utan det krävdes observationer under kanske flera hundra år. Detta har nu krympt till 30 år. Men det har knappast krympt så att man kan se det i nuet.

Stormar och översvämningar

Påståendet om kraftigare stormar, svårare översvämningar, värre värmeböljor och extrem havsnivåhöjning har inte stöd i forskningen. FN:s klimatpanel har inte sett någon ökad trend av cykloner de senaste hundra åren: ”Current data sets indicate no significant observed trends in global tropical cyclone frequency over the past century …” (Fifth assessment report 2013/14, kapitel 2, sid. 216).

I specialrapporten från IPCC 2018 (Global Warming of 1.5 °C) menar man t.o.m. att åtminstone antalet cykloner (till skillnad från deras styrka) kommer att minska med uppvärming över 1,5: ”the total number of tropical cyclones is projected to decrease under global warming” (sid. 204). Man skriver ofta om vad som kommer att hända om vi får ”intensified storms”: störda ekosystem, svårare för människor att återhämta sig efter stormar, skador på skog och koraller etc. Det är om det. Men kommer verkligen stormarna att bli fler och/eller starkare? Specialrapportens syn på detta är inte glasklar.

När det gäller översvämningar hade man i Fifth assessment report inte sett trender som tydde på fler eller större översvämningar: ”There continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale over the instrumental record.” (Fifth assessment report 2013/14, ”Technical summary”, sid. 112). Specialrapporten från 2018 hävdade dock att man nu kan vänta sig viss ökad risk (framtida risk, få faktiska observationer finns) regionalt, men man påpekade också: ”There are studies, however, that indicate that socio-economic conditions will exacerbate flood impacts more than global climate change …” (Specialrapporten, sid. 214).

NASA m.fl. har konstaterat en havsnivåhöjning med ungefär 3 millimeter per år, sedan åtminstone 90-talet. Det är knappast den extrema havsnivåhöjning man målar upp på bortåt en meter till år 2100, som sägs i filmens 37:e minut. Ska man skrämmas med klimatförändringar, så är det förstås viktigt att få väderhändelser som sker idag att framstå som att de saknar motstycke i historien, att de är unprecedented. Det brukar man säga om temperaturer, skogsbränder m.m. I Attenboroughs film säger astrofysikern Jim Hansen att havsnivån tidigare ”has been stable for several thousand years” (filmens 18:e minut). Det är ju precis tvärt om. Havsnivån har både sjunkit och stigit under tusentals år. Situationen har också påverkats av en landhöjning sedan isen från senaste istiden drog sig tillbaka.

a man made disaster on a global scale

Attenboroughs syn på naturen passar in i en tradition av ekologer och naturfilosofer som sett naturen som tämligen statisk, tills människan rubbat balansen.

Efter de inledande braskande klippen uppenbarar sig Attenborough i ett vackert engelskt landskap och säger: ”Standing here in the English countryside, it may not seem obvious, but we are facing a man made disaster, on a global scale. In the twenty years since I first started talking about the impact of climate change on our world, conditions have changed far faster than I imagined.”

Attenboroughs syn på människan som en art som både förstör sig själv och jorden passar in i en tradition av ekologer och naturfilosofer, t.ex. George Perkins Marsh eller Ernst Haeckel, som sett naturen som tämligen statisk eller i balans, som en perfekt maskin – tills människan kom och rubbade alltsammans.

Entomologen och ekologen Stephen A. Forbes skrev i artikeln ”The Lake as a Microcosm” (1887): ”Perhaps no phenomenon of life in such a situation is more remarkable than the steady balance of organic nature, which holds each species within the limits of a uniform average number, year after year …” och vidare att ”Although every species has to fight its way, inch by inch, from the egg to maturity, yet no species is exterminated, but each is maintained at a regular average number which we shall find good reason to believe is the greatest for which there is, year after year, a sufficient supply of food.” En sådan syn på naturen ger knappast utrymme för något darwinistiskt naturligt urval.

Ekologen Daniel Botkin menar i stället att förändring har varit regel i jordens historia, och det gäller även klimatet:

None of these steady-state assumptions are true. Species do not come into instant equilibrium with a new climate; they are always in the process of responding to previous environmental change. There are other factors that limit distribution that are changing over time. Individuals, populations, species have the capability to adjust to a changing environment; otherwise they all would have gone extinct in the past. (Botkin, The Moon in the Nautilus Shell, 2012, sid xiii.)

I Attenboroughs film visas sedan en animerad världskarta, där färger indikerar temperaturförändringar från 1884 till 2018. Kartan är först gul, vit och blå, blir sedan blå och orange, sedan ljusröd och slutligen under 2000-talet mörkröd, som om jorden glöder: ”Our climate is changing because of one simple fact, our world is getting hotter”, säger Attenborough.

Skillnaden i temperatur mellan denna blåvita kalla värld 1884 och vår rödglödgade jord 2018 är cirka 1 grad Celsius! Eftersom det är frågan om medeltemperatur, så bör detta tolkas som att jorden blivit kanske två–tre grader kallare på några ställen och kanske tre–fyra grader varmare på andra. Det är det de olikfärgade färgfläckarna visar. Om detta är bra eller dåligt beror på de lokala förhållandena.

Temperaturhöjningen: orsak och konsekvenser

Även vissa inom IPCC-nätverket är inne på att effekterna av en eventuell framtida temperaturhöjning måste bedömas olika på olika platser. Mike Hulme, numera professor i humangeografi vid Cambridge University, skrev så här (5 februari 2002) i ett av de mail som sedermera läckte ut till offentligheten i den s.k. Climategate-skandalen: ” … the panel text [man diskuterade då IPCC:s Fourth assessment report / KET] does not mention that some people (and countries) may experience benefits as a result of climate change”. (Hela mailet finns här.)

Peter Stott (från UK Meteorological office och Exeter University) säger sedan: ”What we’ve seen is this steady and unremitting temperature trend [bild på kartan igen som glöder], twenty of the warmest years on record have all occured in the last 22 years.”

rolling_stoneaug_2019_hottest

Ibland blir det lite fel. ”Human history” är något annat än ”recorded history”. Och ”recorded history” är något annat än ”historical temperature records”.

Man utmålar ständigt olika sommarmånader olika år till de varmaste sedan man började mäta (ibland t.o.m. varmaste i mänsklighetens historia). Nu senast var det juli 2019 som varit varmast sedan man började mäta.

Vad menar man förresten med varmaste månad? Är det högst medeltemperatur för hela månaden? Eller är det en månad som haft en topptemperatur en viss dag eller vecka? Och talar man om anomalier (avvikelser från platsens ”normala” eller genomsnittliga temperatur under en längre period) eller absolut temperatur (vad termometern faktiskt visar)?

När NASA utropade 2014 till det varmaste året som uppmätts (sedan 1880) glömde man nämna att skillnaden mot 2010, som tidigare ansetts varmast, var 0,02 °C. Felmarginalen angavs också till 0,1 °C. Felmarginalen var således 5 gånger större än den uppmätta (beräknade) skillnaden. Sammanställningen av mätpunktsdata från hela jorden är dessutom så pass osäker att uppgiften om 2014, som det dittills varmaste året sedan 1880, var säkert bara till 38 procent. (Se artikeln ”Nasa climate scientists: We said 2014 was the warmest year on record… but we’re only 38% sure we were right” i Mail Online 18 januari 2015; kanske även här)

Det diskuteras om vi sedan ungefär tjugo år kanske är inne i en uppvärmningspaus (se ”Har den globala uppvärmningen avstannat?”). Men hur kan det pågå en uppvärmningspaus (om det nu gör det) och rekordvärme samtidigt?

Svaret torde vara att den uppvärmning det talats om de senaste åren är så pass liten, tiondelar och hundradelar av en grad, att det också kan ses som ett avtagande av den uppvärmning som ju var mycket mera påtaglig 1920–40 samt 1980–98. Just när det gäller åren 2010 och 2014, så är alltså felmarginalen så stor (och differensen så liten) att förhållandet skulle kunna vara det omvända: att 2010 var varmare än 2014.

Peter Stott säger också: ”What is striking is that this warming trend cannot be explained by natural factors, it is caused by human activities, in particular by use of fossil fuels.”

Varför skulle inte naturlig påverkan kunna vara förklaringen? Varma perioder har ju funnits i tusentals år före både industrialismen och före människan. Det har troligen funnits varma perioder utan särskilt hög koldioxidhalt i atmosfären och ganska svala perioder när koldioxidhalten varit förhållandevis hög (enligt Ernst-Georg Beck 2007 kan CO2-halten runt 1820–30 ha varit högre än nu). Så sambandet är inte säkerställt, åtminstone inte när det gäller koldioxid som främsta regulator av medeltemperaturer över lite längre tidsperioder. Historiskt torde det (även) ha varit solaktivitet, vulkaner, jordaxelns ställning, havsströmmar m.m. som spelade in.

Det bör påpekas att även om de flesta, också s.k. skeptiker, håller med om att jorden blivit någon grad varmare de senaste hundra åren, och att koldioxid förmodligen har en (större eller mindre) roll i detta, så finns det ändå stora osäkerheter. Antalet mätpunkter på jorden för temperatur är inte särskilt stort. GISS/NASA listar nu 7 300 väderstationer, men då ingår även nedlagda stationer, vars data används i historisk statistik och kurvdiagram; i praktiken utnyttjas idag data från kanske cirka 2 000. Särskilt över världshaven är bilden oerhört ofullständig. Hur data från denna ojämna täckning skall sammanställas och beräknas till ett ”globalt medelvärde” är mycket komplicerat och osäkert.

Nyligen har det dessutom presenterats tecken på att databasen HadCrut4, som många temperaturberäkningar bygger på, kanske är behäftad med stora fel. John McLean, vid James Cook University i Townsville i Australien, visar i sin doktorsavhanding från 2017 på ett 70-tal problem med dessa temperaturdata, t.ex. att vissa korrigeringar som alltid måste göras av mätdata också skapar en falsk bild av uppvärmning. (Se vidare McLean, An audit of uncertainties in the HadCRUT4 temperature anomaly dataset plus the investigation of three other contemporary climate issues, diss., James Cook University, 2017.) Även på denna punkt finns det alltså anledning för ett TV-program som gör anspråk på att berätta fakta om klimatet att också nämna de osäkerheter som finns.

IPCC hävdar ofta att man har evidence för det ena eller andra utifrån dels observationer, dels de datorkonstruerade klimatmodellerna. Men dessa modeller kräver ju bevis – då kan de inte gärna ingå i bevisningen. I Specialrapporten från 2018 står det t.ex. på sid. 183: ”Evidence for the assessment of changes to climate at 1.5 °C versus 2 °C can be drawn both from observations and model projections.”

I filmens nionde minut visar Attenborough döda fladdermöss (eg. flyghundar, s.k. flying foxes) i Australien, som trots att de evolutionärt är anpassade till höga temperaturer har dukat under i tusental. Man visar en rörande bild på en liten unge som klamrar sig fast vid sin döda mamma. Peter Stott säger: ”It’s inconceivable that you would se these temperatures without the fact of climate change.”

Man lägger flera döda flyghundar i en skottkärra och man hör någon säga ”it’s climate change in action” (vid tiden 10:27–10:30). Eller rättare sagt, man hörde det i BBC:s originalfilm från april i år, men detta yttrande är nu borttaget i den version som visas i SvT. Det är väl knappast SvT som strukit detta. Det troligaste är väl att BBC fick kritik för uttalandet och tog bort det.

climatechangeinaction_svenska

”If you have two more events like we had, the species are gone”, säger en kvinnoröst, och därefter hörs en mansröst säga ”it’s climate change in action” – men bara i originalfilmen från april. I den version som nu visas i Sverige är det sista yttrandet borttaget.

Att flyghundar dör på detta sätt är känt sedan länge. Faktiskt finns fenomenet dokumenterat redan på 1700-talet. Så här skrev den brittiske marinofficeren Watkin Tench i en reseskildring om sitt besök 1790 i Sydneytrakten, närmare bestämt i Rose Hill, där det var 40–41 grader varmt i december:

An immense flight of bats driven before the wind, covered all the trees around the settlement, whence they every moment dropped dead or in a dying state, unable longer to endure the burning state of the atmosphere. Nor did the ‘perroquettes’, though tropical birds, bear it better. The ground was strewn with them in the same condition as the bats. (Watkin Tench, A Complete Account of The Settlement at Port Jackson, kap. XVII, 1793.)

Till yttermera visso visades nyligen ett annat program i SvT om flyghundarna i Australien, ”Australiens vilda natur” del 4, där många dog av värmen, men inte ett ord om klimatförändringar.

Har skogsbränderna ökat globalt?

Sedan visas oerhört dramatiska bilder på bränder, sedda inifrån en bil och utifrån ett hus, där eld slår ut från alla fönster i en våldsam brand. Attenborough: ”Last year saw record breaking wildfires take hold across the globe.” Michael Mann: ”We’ve seen wildfires break out in Greece, even in the Arctic.” (Att det brinner i kalla länder, t.ex. i Arktis, är inte ovanligt, bara det brännbara materialet är tillräckligt torrt och någon form av antändning sker.) Mann igen: ”We’ve seen a tripling in the extent of wildfires in the western US, in California.” Bilder från en bil som kör på en väg där skogen brinner på båda sidor. En chockad far och son som undkommit intervjuas om hur nära döden de varit.

Skildringen av skogsbranden och de andra bränderna är kanske riktig, men har det verkligen med klimatförändringar att göra? Enligt statistiken har bränderna snarast minskat (se t.ex. statistiken hos NIFC), men det är omdiskuterat om de kanske blivit färre men större. Ett program som ger sig ut för att redovisa fakta borde tala om ifall saker är omstridda. Både i Sverige och USA brann väldiga arealer också i slutet av 1800-talet och på 1930-talet t.ex.

I artikeln ”Global trends in wildfire and its impacts”, publicerad av brittiska Royal Society 2016, skriver Stefan H. Doerr och Cristina Santín bl.a.: ”… global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago.”

I 16:e minuten säger Attenborough: ”I won’t say that all can be due to climate change. Last years extreme weather events meant that millions of people needed humanitarian aid.” Vad vill han ha sagt med detta? Att bilderna från en översvämning i Kerala i Indien, som visas till detta, kanske inte beror på klimatförändringar, men det är så här översvämningar som verkligen beror på klimatförändringar kommer att se ut?

Det här tycks vara filmens främsta retoriska grepp. Allt som visas, skogsbränder, översvämningar och döda flyghundar blir, oavsett vad händelserna beror på, exempel på dramatiska klimatförändringar och att de redan pågår. Och att det kommer att bli värre.

Är issmältningen i Arktis unik?

Man går sedan över till hur isen smälter i Arktis och Antarktis. Andrew Shepherd (klimatforskare, University of Leeds):

In the last year we have had a global assessment of ice losses from Antarctica, from Greenland, and they tell us that things are worse than we expected. The Greenland ice sheet is melting, it’s lost two trillion tons of ice, it’s losing five times as much ice today as it lost 25 years ago.

Här borde programmakarna, om de ville spegla fakta, nämna att ismassorna både i Arktis och Antarktis har ökat och minskat hela tiden under århundradena. Hur de rörelser mot allt mindre sommaris som pågår nu ska tolkas är omstritt. Animationer som visar arktiskt ismaximum under vintern 1979–2006 kan man se här, och arktiskt isminimum under sommaren under samma tid finns här.

Arktis genomgick också en ovanlig uppvärmning 1920–40, som forskarna inte kunnat förklara tillfredsställande. Lennart Bengtsson och medarbetare skrev 2003 inom ramen för arbetet på Max-Planck-institutet i Hamburg om detta:

The Arctic 1920–1940 warming is one of the most puzzling climate anomalies of the 20th century. Over a period of some fifteen years the Arctic warmed by 1.7 °C and remained warm for more than a decade. This is a warming in the region comparable in magnitude what is to be expected as a consequence of anthropogenic climate change in the next several decades. (Bengtsson et al., ”The early century warming in the Arctic: A possible mechanism”, MPI Report 345, 2003.)

Att detta skedde under en peridod när ökningen av atmosfärens koldioxidhalt bara var ungefär 20 procent av dagens, får forskarna att tro att orsaken snarare varit ökad solaktivitet än mänsklig påverkan.

En dansk studie från 2005 av Knud Lassen och Peter Thejll undersökte havsis i östra Grönland mellan år 1500 och 2000 baserat på tidigare undersökningar av bl.a. syreisotoper i isborrkärnor. Lassen och Thejll finner ett isminimum, kanske som idag, på 1500-talet och rejäla maxima någon gång varje sekel 1600–1900. En abrubt minskning av isen skedde också på 1920-talet, liksom i våra dagar. Variationerna tror de beror på bl.a. solaktivitet. Lassen och Thejll skriver avslutningsvis:

The considerations of the impact of natural sources of variability on arctic ice extent are of relevance for concerns that the current withdrawal of ice may entirely be due to human activity. Apparently, a considerable fraction of the current withdrawal could be a natural occurrence. (Lassen & Thejll, ”Multi-decadal variation of the East Greenland Sea-Ice Extent: AD 1500-2000”, Scientific Report 05-02, Danish Meteorological Institute, 2005.)

En studie från 2017 av Paola Moffa-Sánchez och Ian Hall (”North Atlantic variability and its links to European climate over the last 3000 years”, Nature Communications volume 8, 2017) undersöker arktisk is under 3 000 år med hjälp av pollen i havssediment. Enligt den studien torde isen ha täckt mindre områden för 500 år sedan än idag. Men det finns andra studier som kommer till andra resultat, så saken är som sagt omdiskuterad, vilket TV-filmen borde ha nämnt.

Havsnivåhöjningar och korallrev

Filmen tar sedan upp havsnivåhöjningar: ”Rising seas are displacing hundreds of thousands of people”, säger Attenborough. Man får se bilder på översvämmade områden, med människor som sitter på meterstora små bankar med vatten runt om. Colette Pichon Battle (VD för Gulf Coast Center for Law & Policy i Louisiana) säger: ”In the United States Louisiana is on the frontline of this climate crisis, it’s loosing land at one of the fastest rates on the planet. A rate of a football field every 45 minutes.”

Louisiana har en extremt stor landförlust, som till största delen beror på att landet sjunker och har gjort detta i åtminstone hundra år. En global havsnivåhöjning på 3 mm per år (medelvärde) samt en lokal landsänkning på 6 mm ger totalt en havsnivåhöjning av 9 mm per år. Det har knappast med klimatförändringar att göra, däremot har det i viss utsträckning att göra med mänsklig påverkan. Ogenomtänkt vattenbyggnad, samt dragning av pipelines för olja och gas i markerna runt Mississippifloden har påverkat erosionen. Colette Pichon Battle säger att invånarna i Isle de Jean Charles, i låglandet alldeles intill Louisianas kust, har kallats de första klimatflyktingarna i USA. Så är knappast fallet. Landförlusten i Isle de Jean Charles har pågått i åtminstone hundra år.

I filmens 23:e minut säger Attenborough att en tredjedel av världens korallrev har blekts och dött under de senaste tre åren p.g.a. värmepråfrestningar. Jag vet inte vad han har för källa till detta påstående, men det verkar inte stämma med flera artiklar om hur korallreven återhämtar sig, t.ex. Michael D. Fox et al., ”Limited coral mortality following acute thermal stress and widespread bleaching on Palmyra Atoll, central Pacific”, som beskrivs här.

En kinesisk studie antar t.o.m. att korallerna mår bra av värmen: ”We identify abrupt coral reef recovery in the northern South China Sea (SCS) since the last century (especially post‐1960 CE), indicating that the Current Warm Period is an optimal episode for reef growth in the northern SCS.” (Shuang Yan et al., ”Episodic Reef Growth in the Northern South China Sea linked to Warm Climate During the Past 7,000 Years: Potential for Future Coral Refugia”, JGR Biogeosciences, april 2019.) Återigen efterlyser man att filmen i alla fall borde nämna att frågan är omtvistad.

I filmen 26:e och 27:e minut visar man upp några s.k. klimatförnekare, t.ex. Paul Broun, som säger att ingen temperaturökning skett på åtta år. Det är tydligen så dumt att det inte ens förtjänar en kommentar. Möjligen var Broun aningen tidigt ute, men detta är något som diskuteras – även av IPCC (se ”Har den globala uppvärmningen avstannat?”). Ingen signifikant temperaturhöjning har skett (förutom de naturliga fluktuationer som åstadkoms av El Niño-fenomenet) på 20 år (1998–2018).

Lord Lawson visar man också upp som ”förnekare”, när han säger att det även finns ”huge benefits from a warming planet”. Även detta tycks vara så dumt att det inte kräver någon kommentar. Hittills kyliga områden på jorden blir troligen bättre för odling. Jordens växtlighet mår också bra av ökad koldioxidhalt, öknar och andra torra områden har börjat grönska. Detta har dock inte primärt med värmen att göra utan beror på att koldioxid fungerar som en sorts gödning för växter. Lu, Wang & McCabe fann ”extensive areas of ’greening’ in dryland areas of the Mediterranean, the Sahel, the Middle East and Northern China, as well as greening trends in Mongolia and South America.” (”Elevated CO2 as a driver of global dryland greening”, Nature Scientific Reports, februari 2016.)

Se även denna webbsida hos NASA, där det framgår att mellan 25 och 50 procent av jordens grönområden blivit ännu grönare.

I filmens 30:e minut nämner professor Matthew Hansen vid University of Maryland dock ett motsatt fenomen, avskogning. Han visar en karta, där skogar försvinner på stora ytor av jorden (enligt kartan tycks större delen av Sverige och Finland ha nedbrända eller avverkade skogar, hur man nu kommit fram till det).

Hur stora områden det nu än handlar om, så är väl frågan om detta är en klimatfråga eller en avverkningsfråga. Hansen säger att regnskogar bränns ned och ersätts med odlingar av soyabönor eller gummi eller används som betesmark för boskap. Men bland det som påverkar allra mest, säger han, är odlingen av palmolja. Palmolja finns i nästan allt, tillägger Mark Maslin, professor i klimatologi vid University College, London. Ingen nämner dock att palmoljan används som ”miljövänligt” biobränsle.

Permafrosten

Attenborough säger (i 38:e minuten) att förutom allt detta kan vi hotas av ännu värre katastrofer, som kallas tipping points, dvs. att någon process når en punkt där den blir oåterkallelig. IPCC har dock i sin bedömning från 2013/14 övergivit de flesta av dessa farhågor. Vissa problem ser man eventuellt med smältande permafrost som kan avge växthusgaser. Se ”Är klimatapokalypsen inställd?

När Attenborough därefter ska beskriva problemet med permafrosten, blir det missvisande. Han nämner att metangas (en växthusgas 20–30 gånger mer potent än koldioxid) finns under jorden i permafrosten. Man får sedan se ekologen Katey Walter Anthony från University of Alaska gå ut på isen på en vanlig sjö i närheten av Fairbanks i Alaska. Men det är skillnad på metan i vanliga sjöar som avsöndras hela tiden och metan som kan bildas och avges från permafrost om den smälter.

Dr Anthony visar hur det finns bubblor inuti sjöisen, och med lite hett vatten smälter hon det översta lagret. Gasbubblorna kommer ut i luften och man tänder en tändsticka så att gasen flammar upp. Intrycket är förstås mycket spektakulärt. Metanets problem är dock inte att det brinner utan att det effektivare än CO2 blockerar jordens värmestrålning så att den inte försvinner ut i rymden.

Ingen vet hur mycket metan permafrosten (som huvudsakligen finns på norra halvklotet) innehåller, men uppskattningar ligger på 1,7 triljoner ton kol, bundet i organiskt material, som alltså kan bli både koldioxid och metan när och om permafrosten börjar smälta och det organiska materialet bryts ned. En bedömning är att nuvarande uppvärmning skulle kunna leda till att 1 gigaton metan avges från töande permafrost till år 2100. Som jämförelse kan nämnas att sjöar, kärr och andra våtmarker är en större källa till metan, 0,167 gigaton per år, vilket till år 2100 skulle bli 13,36 gigaton.

På sin webbsida visar Dr Anthony för övrigt upp en inte fullt så ominös sida av metanbubblorna. Här arbetar man med ett projekt som ska förse byar i norra Alaska med kok- och värmegas från sjöbubblorna istället för från importerad diesel.

I Specialrapporten från IPCC 2018 (sid. 208) refererar man till en studie, där man tror att metan och koldioxiod i permafrost kanske kommer att kunna bindas av ökad torvbildning: ”Transient releases of CO2 and CH4 may follow permafrost melting, but these occurrences may be compensated by peat growth over longer time scales (Yu et al., 2010).”

Både sol- och vindkraft nämns som alternativ till de fossila bränslena. Inget fel i det, men ett program som vill förmedla ”the facts” borde nog också nämna en del av problemen med dessa energikällor. Först och främst att de har en ojämn energiproduktion och knappast kan vara ett alternativ för utvecklingsländer som vill bygga upp tung industri t.ex. Ett problem med solfångarna, om man nu är rädd för koldioxid, är att de för närvarande tillverkas i länder där el framställs med hjälp av fossila bränslen (Kina t.ex.). Solfångarna kräver ofta enorma arealer, vilket inkräktar på habitat och djurliv, t.ex. skadas fåglar. De kräver också stora mängder vatten bl.a för rengöring, och när de tjänat ut skapar de miljöfarligt avfall. Vindkraftverkens propellrar dödar mängder av fåglar, insekter och fladdermöss som ju ska bevaras för mångfaldens skull.

Det är tråkigt, för att inte säga förödande för opinionen och klimatpolitiken, att medierna inte tar chansen att allsidigt redogöra för forskningsläget, utan ständigt bara för fram att alla forskare är överens om katastrofens annalkande. Jag anser att det är högst kontraproduktivt för den allmänna folkbildningen och för ett genomtänkt beslutsfattande att producera filmer med den här typen av ensidig skrämselpropaganda.