Findings of the summary report:
Climate change’s effects will grow more severe and that spending and planning are needed to guard against future costs. Damage from climate change and the costs of adapting to it could cause the loss of several percentage points of gross domestic product in low-lying developing countries and island states. Climate change could “indirectly increase risks of violent conflicts in the form of civil war and inter-group violence” by “amplifying” poverty and economic shocks.
The most likely damage from climate change will be linked to rising sea levels and temperatures. Those changes could turn the advantages of growing coastal cities into vulnerabilities if interlocking transportation, electrical and information systems fail.
Efforts to adapt could include constructing emergency cyclone and flood shelters like those in parts of Bangladesh, moving generators out of New York City basements that flooded during Hurricane Sandy, changing farming techniques to cope with higher temperatures, and conserving water and curbing pollution in areas threatened with more-frequent droughts.
The “very high confidence” category of climate-change effects included exacerbating more-intense heat waves and fires, increased food- and water-borne diseases, and a steady rise in sea level in certain regions, such as the East Coast of the United States.
World leaders and businesses must act to slow climate change, not just adapt to it. Increasing magnitudes of warming increase the likelihood of severe, pervasive, and irreversible impacts. Some of the warming could have “cascading effects.”The summary of the report, ratified at a five-day meeting in Yokohama, Japan, avoided specific forecasts or timetables or cost estimates, but it described a range of likelihoods and outcomes in an attempt to give decision-makers the tools to set priorities to combat those effects. The IPCC’s new report underscores the need for immediate action in order to avoid the most severe impacts of climate change.
The impact and adaptation report is Part 2 of a four-part assessment by the IPCC. It relied on about 12,000 papers and was written by 309 scientists, who voted on the final version Sunday morning in Japan.
The report attached a “medium confidence” rating to some of those events, but it highlighted the danger of “abrupt and irreversible regional-scale change” if high temperatures hurt the ability of the Arctic boreal tundra or the Amazon forest to store carbon dioxide, or sped the collapse of a continental ice sheet. (Wash Post, 3/30/2014)