There is plenty of evidence to confirm that the polar ice caps are indeed melting and that global warming is to blame. The most noticeable evidence is the fact that the ice caps have decreased drastically in size over the past 100 years or so. Figure 1 displays this visually.
Figure 1 from enviromatters.wikispaces.com
This poses an incredibly dangerous threat to polar bears and other inhabitants of arctic regions, as well as to the ecosystems of the biome. However, the ecosystem disruption in the ice caps is only one of many drastic repercussions of the melting ice caps. An article published by the National Academy of Sciences’ Research Council lists two other majorly destructive consequences of this crisis.
Growing scientific research heavily suggests that changes in the arctic regions are leading to changes in the weather of the mid-latitudes. The increasingly warmer air in the arctic regions is leading to a greater persistence in abnormal weather conditions such as intense snow, intense heat, intense cold, intense rain, essentially any other extreme types of weather, including dangerous storms. “The basic idea is that a warmer Arctic plays games with the jet stream, the stream of air high above us in the stratosphere that carries our weather and that is driven by temperature contrasts between the mid and high latitudes,” writes Chris Mooney of the Washington Post. “If the Arctic warms faster than the mid latitudes do, then the jet stream could slow down, goes the theory. It could develop a more elongated and loopier path, leading to a persistence of particular weather conditions.” Figure 2 shows the elongated, loopy jet stream patterns.
Figure 2 from http://www.washingtonpost.com/news/energy-environment/wp/2015/04/16/the-arctic-is-unraveling-due-to-global-warming-and-the-consequences-will-be-global/
Another destructive side-effect of the meltdown of the ice caps is that it releases greenhouse gasses into the atmosphere, thus increasing global warming. The ice and permafrost (frozen ground) in arctic regions contains massive stores of frozen carbon, “some 1,330 and 1,580 gigatons worth, and that may be a low end estimate,” says The Washington Post. How did carbon get inside the ice caps? The National Research Council explains that dead plants, which are essentially made of carbon, freeze and lock their carbon in place if the climate is cold, but decompose and release their carbon into the atmosphere in warmer climates. Should the ice caps melt and lose their freezing climate, “the volume of carbon emissions could be enough to set back worldwide efforts to reduce emissions from fossil fuel burning by adding an entire new source of greenhouse gases beyond the usual suspects, like fossil fuels and deforestation,” says the Washington Post.