UNITED NATIONS: A UN panel issued on Sunday another warning to policymakers and stressed that countries must make dramatic changes in their fuel consumption patterns, use of technology and even lifestyles to avert catastrophic effects of climate change.

The report by the Intergovernmental Panel on Climate Change (IPCC) said that nations might have to make attempts to remove carbon pollution from the atmosphere, not just limit how much of it comes out of smokestacks and tailpipes.

Speaking at the Climate Leaders’ Summit in Washington, UN Secretary General Ban Ki-moon urged governments to reach an ambitious but achievable agreement to limit temperature rise within two degrees Celsius above the pre-industrial levels, which “the international community has agreed is the upper limit of safety”.

“Climate impacts are already affecting agriculture and food security, human health, water supplies and ecosystems on land and sea,” said Mr Ban.

According to the IPCC report, global greenhouse-gas emissions have risen more rapidly between 2000 and 2010 than in each of the three previous decades.

The IPCC called for international coordination to address the challenges of climate change, for instance by setting up carbon-pricing institutions, promoting CO2 taxes and ramping up investment in renewable energy.

Delaying action now would increase costs later and the desired results would not be achieved if companies and governments advanced “their own interests independently”, warned Ottmar Edenhofer, co-chair of the IPCC’s working group.

He added that taking action “doesn’t mean world community has to sacrifice growth... Climate policy isn’t a free lunch but could be lunch [that’s] worthwhile to buy”.

Studies have shown that the planet has warmed by about 0.8 degree Celsius since 1900. In 2010, about 200 governments agreed to reduce emissions to ensure that temperatures didn’t rise by more than two degrees Celsius above pre-industrial levels.