The Science
Scientific evidence of climate change
— According to the
Intergovernmental Panel on Climate Change (IPCC)
, the leading international body for the assessment of climate change, warming of the climate system is unequivocal. This is evident from observations of increases in global average air and
ocean
temperatures, widespread melting of snow and ice and rising global average sea levels. Download and read the 2011 special report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX).
Climate scientists
have determined that temperature increases should be limited to 2°C — to avoid causing irreversible damage to our planet. To achieve this, global emissions need to peak by 2015 and decline thereafter reaching a reduction of 50 per cent by 2050.
Far-reacing impacts — The impacts of climate change, including floods, droughts, and an increased frequency and intensity of severe weather events, are being experienced across the globe. These impacts are projected to increase over the course of the 21st century. Learn more about extreme weather and climate events .
Climate change affects all aspects of human existence including freshwater resources and management , eco systems , food, fiber and forest products , industry, settlement and society and health . Regional impacts of climate change differ based on geography.
Causes of climate change
— 
Changes in the atmospheric concentrations of Green House Gases (GHGs) and aerosols, in land cover and in solar radiation alter the energy balance of the climate system and are drivers of climate change. Global GHG emissions due to human activities have grown since pre-industrial times, with an increase of 70 per cent between 1970 and 2004. The largest growth in GHG emissions between 1970 and 2004 has come from
energy supply
,
transportation
, and
industry
, while
residential and commercial buildings
,
forestry (including deforestation)
and
agriculture
sectors have been growing at a lower rate.
What can we do — The two primary responses to climate change are mitigation - cutting down on greenhouse gas emissions - and adaptation - acknowledging the changes and putting systems in place in increase our resilience.
Quick fact — Temperatures at the top of permafrost layer have generally increased since the 1980s by up to 3°C. More facts and figures.
