Durban, South Africa – Chairman of the Intergovernmental Panel on Climate Change (IPCC), Dr. Rajendra Pachauri has called on the UN climate conference fractured over the years by varying positions of countries and regions to allow the science of climate change to guide their discussions over the next week and a half.
“May I state most humbly that the discussions in this conference must be guided by the scientific knowledge the IPCC has generated on the human and economic costs of inaction and the direct as well as indirect benefits of early action,” he said Wednesday on the third day of the 192-party conference taking in Africa’s port city of Durban.
“Science can support informed decisions on this issue. It could provide criteria for judging which vulnerabilities might be labeled key,” he told the Plenary of the 17th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC).
Referring to the IPCC’s recently-released Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX), he said global weather- and climate-related disaster losses reported over the last few decades reflect mainly monetized direct damages to assets.
Estimates of annual losses have ranged since 1980 from a few billion to above US$ 200 billion with the highest value recorded for 2005 when Hurricane Katrina struck in the United States.
Economic, including insured, disaster losses associated with weather, climate, and geophysical events are higher in developed countries, the report found.
Fatality rates and economic losses expressed as a proportion of GDP are also higher in developing countries. During the period from 1970 to 2008, over 95% of deaths from natural disasters occurred in developing countries.
Middle income countries with rapidly expanding asset bases have borne the largest burden, the IPCC scientist said.
In small exposed countries, particularly Small Island Developing States (SIDS), losses expressed as a percentage of GDP have been particularly high, exceeding 1% in many cases and 8% in the most extreme cases, averaged over both disaster and non-disaster years for the period from 1970 to 2010.
Dr. Pachauri also said that models project substantial warming in temperature extremes by the end of the 21st century.
“It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur in the 21st century on the global scale,” he said.
It is likely that the length, frequency and/or intensity of warm spells, or heat waves, will increase over most land areas.
“Based on specific emissions scenarios, a 1-in-20 year hottest day is likely to become a 1-in-2 year event by the end of the 21st century in most regions, except in the high latitudes of the Northern Hemisphere, where it is likely to become a 1-in-5 year event.
“The 1-in-20 year extreme daily maximum temperature will likely increase by about 1°C to 3°C by mid-21st century and by about 2°C to 5°C by late-21st century, depending on the region and emissions scenario, “ he told delegates.
It is also likely that the frequency of heavy precipitation or the proportion of total rainfall from heavy falls will increase in the 21 st century over many areas of the globe. Heavy rainfalls associated with tropical cyclones are likely to increase with continued warming.
At the same time droughts will intensify in the 21st century in some seasons and areas due to reduced precipitation and/or increased evapotranspiration.
“The very likely contribution of mean sea level rise to increased extreme coastal high water levels, coupled with the likely increase in tropical cyclone maximum wind speed is a specific issue for tropical small island states,” according to Dr. Pachauri.
In the case of mountain areas there is high confidence that changes in heat waves, glacial retreat and/or permafrost degradation will affect high mountain phenomena such as slope instabilities, movements of mass and glacial lake outburst floods.