The impact of climate change on natural and human systems already can be seen across all oceans and continents, a report from Working Group II of the finds.
The report, , found that the effects of climate change can be observed from the tropics to the poles, on small islands and across large continents, and in both wealthy and poor countries. They include changes in precipitation and snow and ice melt, which in turn are affecting the quantity and quality of water resources; changes in the geographic ranges, migration patterns, and numbers of many terrestrial, freshwater, and marine species; and an increase in extreme weather events such as heat waves, droughts, floods, cyclones, and wildfires. The report also found that people who are socially, economically, culturally, politically, institutionally, or otherwise marginalized are especially vulnerable to the effects of climate change, which tend to exacerbate food insecurity, loss of livelihood, and poverty.
While it can't be eliminated, climate change risk can be reduced, the report argues, by bolstering preparedness, limiting people's exposure to its worst effects, and curtailing activities that contribute to global warming. Still, while some cities and countries have begun to implement adaptation measures, many of those measures are backward-looking rather than aimed at preparing for a markedly different future.
"Part of the reason adaptation is so important is that the world faces a host of risks from climate change already baked into the climate system, due to past emissions and existing infrastructure," said Working Group II co-chair Vicente Barros.
The report is part of the of the IPCC, which was established by the and the in 1988 to provide a clear scientific assessment of the current state of knowledge in climate change science as well as the potential environmental and socioeconomic impacts of climate change. A final synthesis of the findings of all three working groups will be published in October 2014.
"With high levels of warming that result from continued growth in greenhouse gas emissions, risks will be challenging to manage, and even serious, sustained investments in adaptation will face limits," said Working Group II co-chair Chris Field. "Understanding that climate change is a challenge in managing risk opens a wide range of opportunities for integrating adaptation with economic and social development and with initiatives to limit future warming. We definitely face challenges, but understanding those challenges and tackling them creatively can make climate-change adaptation an important way to help build a more vibrant world in the near term and beyond."