Global Warming – The background to UKIP’s scepticism

16-11-2006

Alarm over the prospect of the Earth warming is not warranted by the agreed science or economics of the issue. Global warming is happening and man is responsible for at least some of it. Yet this does not mean that global warming will cause enough damage to the Earth and humanity to require drastic cuts in energy use, a policy that would have damaging consequences of its own. Moreover, science cannot answer questions that are at heart economic or political, such as whether the Kyoto Protocol is worthwhile. This paper summarizes current genuine issues in global warming research and seeks to set the record straight on scare stories that have been exaggerated by the media and vested interests such as environmental pressure groups.

1. The Science

• There is no “scientific consensus” that global warming will cause damaging climate change. Claims that there is such a consensus mischaracterise the scientific research of bodies like the United Nations Intergovernmental Panel on Climate Change (IPCC) and the U.S. National Academy of Sciences (NAS). • Scientists do agree that:
(1) Global average temperature is about 0.6°Celsius—or just over 1°Fahrenheit—higher than it was a century ago;
(2) Atmospheric levels of carbon dioxide (CO2) have risen by about 30 percent over past 200 years; and
(3) Carbon dioxide, like water vapour, is a greenhouse gas whose increase is likely to warm the Earth’s atmosphere.1

• Scientists do not agree on whether: (1) we know enough to ascribe past temperature changes to carbon dioxide levels; (2) we have enough data to confidently predict future temperature levels; and (3) at what level temperature change might be more damaging than beneficial to life on Earth.

• The NAS reported in 2001 that, “Because of the large and still uncertain level of natural variability inherent in the climate record and the uncertainties in the time histories of the various forcing agents…a causal linkage between the build-up of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established.” It also noted that 20 years’ worth of data is not long enough to estimate long-term trends. 2

• The temperature rise of 0.6°C over the last century is at the bottom end of what climate models suggest should have happened. This suggests that either the climate is less sensitive to greenhouse gases than previously thought or that some unknown factor is depressing the temperature.3

• Predictions of 6°C temperature rises over the next 100 years are at the extreme end of the IPCC range, and are the result of faulty economic modelling, not science (see economics section below).

• Both James Hansen of NASA (the father of greenhouse theory) and Richard Lindzen of MIT (the most renowned climatologist in the world) agree that, even if nothing is done to restrict greenhouse gases, the world will only see a global temperature increase of about 1°C in the next 50-100 years. Hansen and his colleagues “predict additional warming in the next 50 years of 0.5 ± 0.2°C, a warming rate of 0.1 ± 0.04°C per decade.”4

• Evidence from satellite and weather balloon soundings suggests that the atmosphere has warmed considerably less than greenhouse theory suggests.5 There is a disparity between the surface temperature measurements, which cover only a small fraction of the Earth but show sustained warming, and these measurements, which cover the whole atmosphere and show only a very slight warming.

• The NAS has confirmed this disparity as real.6 Recent studies analyzing data from the lower atmosphere suggest that temperature anomalies fall by altitude when greenhouse theory suggests they should rise.7

• New research also suggests that the role of greenhouse gases in warming has been overestimated, as factors like atmospheric soot,8 land use change,9 and solar variation10 all appear to have played significant parts in recent warming.