OTTAWA -- The Intergovernmental Panel on Climate Change issued a synopsis of its latest report Friday, concluding that it's "extremely likely" that human activity is the dominant cause of global warming. Among its conclusions:
- Atmospheric concentrations of carbon dioxide (CO2), methane and nitrous oxide have reached levels unprecedented in at least the last 800,000 years.
- Sea levels will rise between 26 and 82 centimetres by the end of the century, compared with a projection of 18-59 centimetres in the previous report.
- CO2 concentrations have increased by 40 per cent since pre-industrial times, primarily from fossil fuel emissions.
- Based on four different scenarios with different emissions controls, global average temperatures will rise by 0.3 to 4.8 degrees C this century.
- CO2 emissions from burning fossil fuels and producing cement were 54 per cent higher in 2011 than in 1990.
- Arctic sea ice has retreated over the period between 1979 and 2012 at a "very likely" rate of between 3.5 and 4.1 per cent per decade. The range was 9.4 to 13.6 per cent for sea ice that persists year-round.
- Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90 per cent of the energy accumulated between 1971 and 2010.
- By the end of this century, the area covered by permafrost will decline by between 37 per cent and 81 per cent.
Source: IPCC
