Human impact on global warming ‘extremely likely’

Humans are the "dominant cause" of global warming since the mid-20th century, according to an assessment by the Intergovernmental Panel on Climate Change (IPCC).

The findings state that better observations, as well as improved understanding and climate models, have added to the evidence that human influence on the climate system is clear.

Dr Rajendra Pachauri, the chairman of the IPCC, said a carbon tax, which would force power companies and manufacturers to reduce their fossil-fuel use, was crucial in avoiding global warming.

“An extremely effective instrument would be to put a price on carbon. It is only through the market that you can get a large enough and rapid enough response,” he told The Independent. 

The IPCC said warming in the climate system was “unequivocal” and that since 1950, many changes have been observed throughout the climate systems that are unprecedented over decades to millennia.

In addition, the report found that each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.

Thomas Stocker, Co-Chair of the working group responsible for the report, said: “Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

“Global surface temperature change for the end of the 21st century is projected to be likely to exceed 1.5°C relative to 1850 to 1900 in all but the lowest scenario considered, and likely to exceed 2°C for the two high scenarios.

“Heat waves are very likely to occur more frequently and last longer. As the Earth warms, we expect to see currently wet regions receiving more rainfall, and dry regions receiving less, although there will be exceptions,” he added.