That has been puzzling, because the polar regions are thought to be more sensitive to warming trends than the rest of the globe.
Mammals have thermoreceptive elements sensitive to warming or cooling within their brains, particularly in the spinal cord and the hypothalamus, a region at the base of the forebrain.
The temperature of subsea permafrost, near −1 °C (30 °F), is no longer as low as it was in glacial times and is therefore sensitive to warming from geothermal heat and to the encroaching activities of humans.
As can be seen clearly in maps of temperature change (such as those created by Nasa), the increase has been particularly steep in the Arctic, where the climate system is more sensitive to warming than most of the rest of the world, partly due to feedback loops in the local climate that amplify the warming.
This is necessary, they say, because global warming will affect developing countries more than rich ones, partly because tropical and subtropical lands are more sensitive to warming than cold or temperate ones, and partly because rich people can afford better flood controls and drought-resistant seeds than poor ones.
The vast boreal forests or Siberia and Canada are dying back faster than was expected in 2007, and may be more sensitive to warming than was then thought.On the other hand, there are substantial areas where the influence of the climate is modest compared with other factors.
Red birch litter was more sensitive to warming compared with dragon spruce needle.
If tropical forests globally are as sensitive to warming, the authors suggest, they could soon become a major source of the greenhouse gas instead of a sink.
These recent trends indicate that Mount Rainier's glaciers are very sensitive to warming and could grow again with modest changes in temperature or precipitation, the scientists say.
