Emissions legacy threatens 'abrupt' climate change

New research suggests that the decisions of this generation will leave a legacy of increasingly abrupt climate change over the next millennium unless there is a major reduction in C02 emissions.

The report from the Tyndall Centre for Climate Change Research and Environment Agency is the first study to comprehensively examine impacts beyond the end of this century.

The study indicates that the UK will need to make major emissions reductions over the next couple of decades as part of a global effort to prevent abrupt climate changes.

Temperatures could increase by up to 15°C and seas could rise by up to 11.4m, flooding low-lying areas of the UK; the UK’s climate could resemble that of today’s tropics by the year 3000.

Environment Agency Chief Executive, Barbara Young, said the new research showed that the next 25 years were crucial in making tough decisions on reducing the impacts of climate change.

“We are running out of road on decision making - unless we dramatically change the use of fossil fuels then we will be committing future generations to the most severe impacts of climate change,” she said.

The study projects climate change over the next millennium, examining the impacts across the centuries. Increasing CO2 emissions lead in one model to an abrupt climate change where sea temperatures plunge by 3°C as a result of the collapse of warm sea currents.

A second abrupt change occurs with the rapid disappearance of the Arctic sea ice. This warms Arctic seas by up to 8°C and land temperatures at UK latitudes by up to 5°C in the space of a couple of decades.

The report says that by the year 3000:

• Global and regional warming could more than quadruple after 2100;
• Temperatures could rise from 1.5°C if emissions are minimised to as much as 15°C if we continue burning fossil fuels;
• Sea levels will still be rising at the end of this millennium and could reach 11.4m by year 3000;
• Abrupt climate change events could occur;
• Abrupt changes may be triggered many decades before they actually occur. Even after emissions have completely ceased there is still a legacy from decades past.
• Ocean pH is predicted to fall dramatically posing a threat to marine organisms, such as corals and plankton;
• Potential climate changes could be much greater, and avoidance of dangerous climate change even harder, than currently projected

“We now know from this report that we are walking off a shorter plank than we previously thought - the research shows far more dangerous and dramatic climate change effects appearing much earlier than previously predicted – tough decisions are needed soon,” Barbara Young said.

The report's lead author, Dr Tim Lenton of the Tyndall Centre and University of East Anglia, said: "We present a sobering picture of potential climate change on the millennial timescale. Whilst most studies stop at year 2100 with temperatures and sea level rising we explored where they are heading into the next millennium.

"Only by starting to reduce CO2 emissions now, and continuing to reduce them can we avoid dangerous climate changes on the millennial time-scale, including the gradual melt of the Greenland ice sheet" he said.

(SP/GB)