IPCC climate change report : main points

UN panel says human influence on changing of climate system is now ‘clear’

 U.N. Secretary-General Ban Ki-moon during a news conference on the IPCC report. Photograph: Niels Ahlmann Olesen/Scanpix Denmark/Reuters

U.N. Secretary-General Ban Ki-moon during a news conference on the IPCC report. Photograph: Niels Ahlmann Olesen/Scanpix Denmark/Reuters

 

The UN’s Intergovernmental Panel on Climate Change has issued its fifth assessment report today. Here are its main points.

* Warming of the climate system is “unequivocal”, and the human influence on changing it is now “clear”.

* The period from 1983 to 2012 was likely the warmest 30-year period of the last 1,400 years in the Northern Hemisphere.

* Atmospheric concentrations of carbon dioxide, methane and nitrous oxide are “unprecedented in at least the last 800,000 years”.

* Tackling climate change will require “substantial and sustained reductions” in greenhouse gas emissions to limit the risks.

* Without additional mitigation, warming poses a high risk of severe, widespread, and irreversible impacts globally by 2100.

* Delaying action will “substantially increase the challenges” to limit global warming below 2 degrees, relative to pre-industrial levels.

*Surface temperature is projected to rise over the 21st century under all emission scenarios, with much of it occurring in the oceans.

*Heat waves are likely to occur more often and last longer, and extreme precipitation events will become more intense and frequent.

*If temperatures were to rise above 4 degrees, risks include “substantial species extinction” as well as global and regional food insecurity.

*Impacts are projected to slow down economic growth, make poverty reduction more difficult and further erode food security,

*Climate change is expected to lead to increases in ill-health in many regions, especially in low-income developing countries.

*Without additional mitigation, warming poses a high risk of severe, widespread, and irreversible impacts globally by 2100.

*Emissions can be “substantially reduced” through changes in consumption patterns and adoption of energy savings measures.