White-tailed ptarmigan cover. The white-tailed ptarmigan was introduced into the Sierra Nevada of California, Wallowa Mountains in Oregon, and Uinta Mountains of Utah in the 1970s. It may have been native here during the early Pleistocene but became locally extinct due to climate changes with greater snow-cover in spring impacting on its breeding season. Alternatively, it may have been unable to colonize the Sierra Nevada because of the barriers provided by the Columbia River and the Great Basin, and the low altitudes of the intervening South Cascades. This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring
Climate change in the Arctic pathway suggests that methane from seabed permafrost will progress rather slowly, instead of abrupt changes. However, Arctic cyclones, fueled by global warming and further accumulation of greenhouse gases in the atmosphere could contribute to more release from this methane cache, which is really important for the Arctic. An update to the mechanisms of this permafrost degradation, implying the possibility of being close to an acceleration of methane release was published in 2017. Changes in vegetation are associated with the increases in landscape scale methane emissions. The growing season has lengthened in the far northern latitudes, bringing major changes to plant