Sea level likely to rise up to 70 cm by 2100

Ocean levels could significantly rise up to 70 cm by 2100 due to climate change and even the most extreme geoengineering approaches would not be able to stop sea levels from rising, according to a new study. The study published in the journal Proceedings of the National Academy of Sciences ( PNAS) proposes that as many as 150 million people could be affected as ocean levels could rise by 30 cm to 70 cm. 

Scientists led by John Moore from Beijing Normal University, China, said that to combat global warming, people need to concentrate on sharply curbing greenhouse gas emissions and not rely too much on proposed geoengineering methods. "Substituting geoengineering for greenhouse emission control would be to burden future generations with enormous risk," said Svetlana Jevrejeva of the UK's National Oceanography Centre, a co-author of the study. 

Jevrejeva and colleagues from China, Finland and Denmark wanted to see how five geoengineering solutions will affect sea levels. Geoengineering falls into two main types: limiting the effect of the sun's rays, or changing the carbon cycle in some way. The former doesn't change atmospheric CO2 levels in any way, whereas the latter does. 

The team used a well-established model to look at the effect of firing a large amount of sulphur dioxide into the atmosphere, putting mirrors in space, planting huge numbers of trees, biochar (turning plants into a type of charcoal in soil where they boost crop productivity) and switching to bio-energy. 

They investigated how these methods would affect climate change under different CO2 emissions scenarios. They found that using bio-energy for power while capturing the emitted CO2 and storing it deep underground is likely to be the least risky and the most publicly acceptable solution to tackle climate change. This would also lead to fewer fossil fuels being burnt for energy. But this solution wouldn't be as effective as using aerosols or giant mirrors in space at slowing sea level rise.

Link PTI

Warming could reduce rainfall

Scientists have warned that global warming could reduce rainfall, contrary to the belief that rising temperatures lead to increase in overall precipitation levels.

Previous studies have shown that rainfall will increase globally by 2-3% for every degree Celsius that the Earth's surface heats up.

But, scientists at the University of Leeds who looked at a range of climate change scenarios, found that rainfall may actually decline if temperature in the atmosphere continues to increase. "Clearly there's something else going on," said lead author Timothy Andrew.

"We found that precipitation isn't just affected by temperature change at the surface. It also responds directly to increased heating in the atmosphere," Andrews said.

And because the atmosphere responds to heating much more quickly than the surface the effect on rainfall is also much faster, Andrewssaid.

Link TOI

Rs 25,000 crore kitty for tackling climate change: Ramesh

India is going to be affected "the most" by climate change but the government has made a provision for Rs 25,000 crore to mitigate its impact, environment minister Jairam Ramesh said.

Replying to a debate on a private member's resolution for setting up a fund for dealing with climate change, the minister said money is being raised through cess on coal and compulsory afforestation fund. Besides, the finance ministry has sanctioned Rs 5,000 crore as recommended by 13th Finance Commission.

"Climate change is a reality...It is a serious issue. We are going to be affected the most by climate change. But we are taking steps to mitigate it," he said. The country is witnessing Monsoon extending to the last week of August, "which is unusual".

About 220 scientists from 120 research institutions are working on assessment of the impact of climate change on agriculture, water, health and forest. The research covers impact on the Himalayan glaciers, North Eastern region, Western Ghat and coastal areas. Their report will be available in the next two months, Ramesh said.

Giving a break-up of the fund plan, he said Rs 10,000 crore is already available under the Compensatory Afforestation and Management Planning Authority (CAMPA). "The first tranche of Rs 10,000 crore will be distributed to the state government," he said. Contributions to the CAMPA come from business establishments taking up activities in forest land.

Another fund of Rs 10,000 crore would be generated by 2015 from clean energy cess on coal. The cess has become operational and Rs 3,000 crore would be available under it this fiscal. The funds (Rs 5,000 crore), recommended by the 13th Finance Commission would be released in the next five years to states according to their forest cover. Chhattisgarh, Orissa, Andhra Pradesh and Madhya Pradesh will be the major beneficiaries under the scheme.

Link TOI