The us has perpetually been in denial about global warming, especially after the Earth Summit in Rio De Janerio held in 1992, but a recent report released by the us Climate Change Science Program (ccsp) may shake it out of its complacency. The report adds ammunition for lobbies within the us and forces outside it for pushing the world’s only superpower towards signing the 1997 Kyoto Protocol on global warming. It does this by demystifying the debate over the contribution of human activity to climate change.

While science has increasingly shown that climate change is induced by human action, industry and the us government have called scientific findings “hallucinations”. br>

The anomaly

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The ccsp report, published on May 2, 2006, claims to be one step ahead of earlier reports by the Intergovernmental Panel for Climate Change (ipcc) and the National Research Council (nrc).

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ipcc’s third assessment report in 2001 had brought out that there was an increase in the overall average global temperature by 1° c since the late 1950s.

The problem lies in the difference in data obtained for surface temperatures and atmospheric temperatures.

While surface temperature data showed substantial warming, early versions of satellite and radiosonde (a probe attached to weather balloons) data showed little or no warming above the surface.

They showed a significant difference in the rise of global average temperatures in the lowest 8 km of the atmosphere (+0.05 ± 0.10° c per decade) and the global average surface temperature (+0.15 ± 0.05° c per decade). The difference in the rate of warming of the surface and the atmosphere was found to be statistically significant when compared with climate models. Climate models, on the other hand, showed that due to increased concentrations of greenhouse gases, temperatures increase in the lower atmosphere as well as on the surface. The ipcc report was criticised by many because it couldn’t explain this anomaly. The 2001 nrc report on climate change was also criticised on the same grounds. Such debates led to a certain amount of confusion regarding the ‘actual’ reason for climate change. Reason enough for the us to stall efforts to curb greenhouse gas emissions.

The recent ccsp report, Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences, has not only resolved previously reported discrepancies between the amount of warming near the earth’s surface and the higher atmosphere, but also strengthened the link between rising temperatures and human induced greenhouse gases, thereby increasing our understanding of the causes behind the observed climate changes.

Energy expert John Holdren has noted that without change the world is headed for a considerable temperature increase, a scenario he calls the “roasted world”.

The significance of this report is not restricted to scientific circles only. It has political implications as well, because the scientific establishment has now spoken out against state gagging and public awareness about the problem has been increasing. In the past, the us has been accused of manipulating reports and barring scientists from speaking about the harms of global warming in public.