A report compiled by hundreds of the world’s top climate scientists will paint a bleak picture of climate change and say that evidence of the negative human impact on the environment is ”widespread”, the Independent reported on Monday.
A draft of a report by the United Nations’s Intergovernmental Panel on Climate Change (IPCC), a copy of which was seen by the newspaper, said that temperature increases of between 2°C and 4,5°C are highly likely this century, but gains of 6°C ”or more” cannot be ruled out.
The report also makes a strong link between increases in man-made carbon dioxide emissions and climate change, according to the Independent.
”Confidence in the assessment of the human contributions to recent climate change has increased considerably since the” last such report, released in 2001.
In that report scientists forecast a global atmospheric temperature increase of between 1,4°C and 5,8°C by 2100.
”Anthropogenic [man-made] warming of the climate system is widespread and can be detected in temperature observations taken at the surface, in the free atmosphere and in the oceans,” said the draft of the report, due to be published on Friday in Paris.
”It is highly likely that the warming observed during the past half century cannot be explained without external forcing [human activity].”
According to the paper, the report also warned of ”positive” feedbacks, which could play a role in accelerating temperature increases.
As the world warms, it causes increased evaporation, leading to higher concentrations of water vapour, thereby exacerbating the greenhouse effect. The report noted that water vapour concentrations over oceans have increased by 4% since 1970.
The IPCC’s climate models also warn that rising temperatures will hamper the planet’s natural ability to absorb carbon dioxide. Heat waves are likely to be more intense, more frequent and longer-lasting, and tropical storms and hurricanes will probably be stronger.
The Arctic will likely be ice-free in the summer, and mountain glaciers, ice caps and ice sheets will continue to melt, according to the draft of the report. – Sapa-AFP