In its latest report Working Group II of the Intergovernmental Panel on Climate Change (IPCC) says that the effects of climate change are already occurring on all continents and across the oceans.
"Observed impacts of climate change have already affected agriculture, human health, ecosystems on land and in the oceans, water supplies, and some people's livelihoods," it said, noting that in many cases the world is 'ill-prepared' for risks from a changing climate.
The report concludes that responding to climate change involves making choices about risks in a changing world. It says that the nature of the risks of climate change "is increasingly clear, though climate change will also continue to produce surprises."
The report finds that risk from a changing climate comes from vulnerability or lack of preparedness, and exposure (people or assets in harm's way) overlapping with hazards (triggering climate events or trends). Each of these three components can be a target for "smart actions" to decrease risk, it says.
"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," says Chris Field, co-chair of Working Group II.
Adaptation to reduce the risks from a changing climate is now starting to occur, but with a stronger focus on reacting to past events than on preparing for a changing future, according to Field.
The report, titled Climate Change 2014: Impacts, Adaptation, and Vulnerability, from Working Group II of the IPCC, was produced by 309 co-ordinating lead authors, lead authors, and review editors, drawn from 70 countries. It comprises two volumes: first contains a summary for policy makers, a technical summary and chapters assessing risks by sector and opportunities for response; the second assesses risks and opportunities for response by geographic region.
The Working Group I report was released in September 2013. The Working Group III report will be released in April 2014, and a synthesis report is expected in October 2014.