All things well

Sticking their head in the sand

From time to time we may come across people who either:

a) deny that climate change is happening, or
b) say that climate change is normal and nothing to worry about, or
c) deny that the present climate change is the result of human activity.

Such people may present various convincing and scientific-sounding arguments.  Some of them may even be Republican politicians (most of whom, apparently, don’t believe that climate change poses a threat).

It is important, where we can, to answer such arguments. Back in the 1950s there was an overwhelming scientific consensus that smoking tobacco is dangerous to health.  The tobacco companies produced lots of supposedly scientific studies and quotes from “scientists” to show that it was not harmful.  Their aim was not to win the argument (they knew they could not) but to create enough doubt in the minds of most people to prevent any action being taken.  The same is true today with climate change.  Doubt leads to inaction.

If we come across such people it helps to know how to spot the standard arguments and how to deal with them.  This is a short guide, which I hope may prove helpful.  All of these issues are covered in depth in a New Scientist article: Climate Change: a guide for the perplexed

1.Global temperatures have been falling over the last decade. People saying this may cite a Met Office Hadley Centre report which stated that 1997/98 was the warmest year and that since 2003 temperatures have cooled.  In fact the Met Office now says that the ten warmest years on record have been since 1997 (see http://www.metoffice.gov.uk/corporate/pressoffice/2008/pr20081216.html ) and that human activity is the cause.  The earlier data did not take into account sea temperatures (which cover 2/3 of the earth’s surface).  Measurements from satellites also appear to show global cooling.  In reality this is evidence of the greenhouse effect, because the earth is losing less heat. (If you look through a thermal imager at two people at the North Pole, one wearing a T-shirt and the other wearing full insulated furs, the one wearing the furs will appear cooler)  For a full discussion of this see See http://www.newscientist.com/article/dn14527-climate-myths-global-warming-stopped-in-1998.html
A variation of this argument is that Antarctic temperatures have been falling. This may be true, but is the result of changes in circular winds at the antarctic preventing warmer air reaching it. It is not evidence that the planet as a whole is cooling. See http://www.newscientist.com/article/dn11648

2. Historically CO2 levels have been much higher.  This is true, but not something to take comfort in.  The highest CO2 concentrations were during the Triassic period when the earth was much hotter and drier than now.  The poles were ice-free and sea levels were high. Much of the USA was a shallow lagoon!  Over millions of years that CO2 was captured by plants and trees and deposited in the earth in the form of fossil fuels.  By burning fossil fuels we are busy reversing the process.

3. Rising CO2 is a result of global warming, not the cause of it. This is a partial truth, and again not something to give us any comfort.  The oceans are huge sinks of dissolved CO2.  As temperatures rise the capacity of the oceans to store CO2 goes down and some of the dissolved CO2 is released.  Historically, it may be true that rises in CO2 have followed global temperature rises.  But historically climate change was not caused by humans burning fossil fuels.  The scary thing is that this is another of those ‘tipping points’ where human activity can trigger an accelerating feedback loop.  See http://www.newscientist.com/article/dn11640

4. Climate change is a natural phenomenon which happens independently of human activity.  Again, this is a partial truth.  In geological terms, humans have only been around very very recently, so obviously we have not been the cause of the quite large climate variations which have happened in the past.  Other causes of climate change include sunspot activity (lots of sunspots = lower temperatures) atmospheric dust caused by volcanos or meteorite impact (perhaps triggering ice-ages) and slight changes in the earth’s tilt and orbit (Milankovich cycles). However none of these factors can explain the current warming. Sunspot activity has a relatively small impact on climate, and there is no correlation between sunspot activity the the warming over the last 40 years. Milankovich cycle theory does not predict any change in the next 20,000 to 50,000 years. And we don’t have any major volcanoes or meteorites happening right now.  See http://www.newscientist.com/article/dn11650

5.  Lots of eminent scientists question global warming. This depends on what you call ‘lots’ and ‘eminent’. The Inter-governmental Panel on Climate Change represents a cautious consensus position of thousands of scientists and scientific organizations. A January 2009 poll of 3146 earth scientists found that 82% answered yes to the question: “Do you think human activity is a significant contributing factor in changing mean global temperatures?”. Of the 77 climatologists actively engaged in research, 75 answered yes (97.4%). The scientists most likely to answer no were petroleum geologists and meteorologists. Even scientists funded by the coal and oil industry reported back in 1995 that ‘The scientific basis for the Greenhouse Effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied,’ (see http://www.nytimes.com/2009/04/24/science/earth/24deny.html)  In fact it is rare to have such a high degree of scientific consensus.  See http://www.newscientist.com/article/dn11654

6. It is a conspiracy to keep the developing nations from advancing economically. Al Gore has made $50 million from his film. The sad facts are that global warming will hurt the poorest (most of whom are in developing nations) most and first. We are already seeing the results in the form of rising food prices – something that will only get worse.  Many of the scientists involved in the IGPCC are from developing nations, including the chairman Rajendra Pachauri from India.
Al Gore went on record a few days ago to say that everything he has made from the film, the book and his green investments, has gone into a not-for profit educational charity.  See http://www.youtube.com/watch?v=LMJ3Xow9ZGM&feature=player_embedded

7. Climate change may be a good thing and we will adapt to it.

civilisation has become possible in a fairly narrow range of temperatures

On a cold winter’s morning when you are struggling to keep warm it can be tempting to think this way. But it ignores the incredible fragility of the earth’s ecosystems. Species adapt to a particular climate and environment and the kind of rapid change we are experiencing (and will continue to experience) leads to mass extinctions. No species is an island. The loss of any one species affects many more. More importantly, this ignores the fact that we are not talking a minor change. So far we have only experienced less than 1C rise on pre-industrial temperatures. If we are to limit temperatures to a 2C rise, we will need to cut back emissions to half of 1990 levels by the year 2050. If we continue on our present path (ie, do nothing) then we are talking about a catastrophic 5-6C rise by the end of the century. Note this is an average temperature rise. Over land it will be much higher.

Unless we can cut emissions by half by 2050 we are looking at catastropic temperature rises (source: Nature, May 2009)

With that we can expect 50% of species lost, vast deserts in what are currently the world’s food baskets and up to 2M sea levels rise.  See http://climateprogress.org/2009/03/22/an-introduction-to-global-warming-impacts-hell-and-high-water/

(For the graphics and much more information I am indebted to http://climageprogress.org , the indispensible blog on the subject.