By David L. Brown
A new report just issued by the NASA Goddard Institute for Space Studies concludes that 2010 to-date is the warmest year on record. This continues on a trend that has been observed over a period of time. The draft report, “Global Surface Temperature Change,” is available as a PDF here. The paper was written by James Hansen and his associates and will be submitted for journal publication soon.
A major step in this latest analysis was to quantify the so-called “urban effect” on warming, with the researchers concluding “that urban effects on analyzed global change are small.” Other steps were taken to fine-tune global warming data by comparing alternative analyses, and addressing questions about perception and reality of global warming.
We conclude that global temperature continued to rise rapidly in the past decade, despite large year-to-year fluctuations associated with the El Nino-La Nina cycle of tropical ocean temperature. Record high global temperature during the period with instrumental data was reached in 2010.
The new data uses satellite measurements of nightlights as a means of quantifying any urban warming effect by using the nightlights as a proxy to determine population density near reporting stations, allowing a correction factor to be applied to data obtained from the urban areas. This is particularly useful in the United States but not necessarily in other places of the world, because the U.S. has more recording stations and uses more energy. When those differences were taken into account, the researchers learned somewhat to their surprise that “The nightlight adjustment reduces the 1880-2009 global temperature change by an insignificant 0.004°C relative to the prior population-based urban adjustment.” The report also introduces adjusted ocean surface temperatures and new analysis of data from the Arctic and Antarctic.
Here is an image from the report showing nightlight emissions worldwide, clearly showing the predominate energy use in advanced countries.
Global warming does not take place evenly from one place to another, and the report explains these differences thus:
Warming in these recent decades is larger over land than over ocean, as expected for a forced climate change, in part because the ocean responds more slowly than the land due to the ocean’s large thermal inertia. Warming during the past decade is enhanced, relative to the global mean warming, by about 50 percent in the United States, a factor of 2-3 in Eurasia, and a factor of 3-4 in the Arctic and the Antarctic Peninsula.
Warming of the ocean surface has been largest over the Arctic Ocean, second largest over the Indian and Western Pacific Oceans, and third largest over most of the Atlantic Ocean. Temperature changes have been small and variable in sign over the North Pacific Ocean, the Southern Ocean, and the regions of upwelling off the west coast of South America.
The draft paper also addresses the misconceptions that arise from confusion about the difference between climate and weather. The scientists write:
Public opinion about climate change is affected by recent and ongoing weather. North America had a cool summer in 2009, perhaps the largest negative temperature anomaly on the planet (Figure 14a). Northern Hemisphere winter (Dec-Jan-Feb) of 2009-2010 was unusually cool in the United States and northern Eurasia. The cool weather contributed to increased public skepticism about the concept of “global warming”, especially in the United States. These regional extremes occurred despite the fact that Jun-Jul-Aug 2009 was second warmest (behind Jun-Jul-Aug 1998) and Dec-Jan-Feb 2009-2010 was second warmest (behind Dec-Jan-Feb 2006-2007).
The new report adds another body of evidence to demonstrate that climate change is real. It will no doubt be ignored by the ignorant, denied by the deniers, and condemned by the self-interested. Meanwhile, Nature will continue on her course despite all the misinformation, propaganda, and deception that mere mortals bring to the issue.