A panel of economists including three Nobel laureates recommend as a fix for the global threat of climate change that global temperatures should be kept in check by spraying clouds with drops of seawater to help make them bigger and whiter and more reflective of the sun’s rays. Besides, whitening clouds, white roads and rooftops would also be a big help according to the US Energy secretary.

It may seem a bit off the wall but President Obama's Energy secretary, Dr. Steven Chu, the winner of the Nobel Prize in Physics in 1997; a former head of the Energy's Department's Lawrence Berkeley National Laboratory and a strong advocate of renewable energy and conservation, said in London in July that whitening the world's roofs and roads would have the same effect on global warming as removing all the world's cars for 11 years.

Chu's comments were based on recent research from Arthur Rosenfeld, a former colleague of Chu's. The reference to all cars for 11 years number is meant to be illustrative -- no one really expects all roofs and all roads will be painted white.

But for new projects and some renewals, it does make sense.

A white roof has three benefits:

• It keeps buildings cooler, reducing the amount of energy required for air conditioning.
• It reduces the so-call "heat island" effect, the heating up of entire urban areas which then causes other buildings in the vicinity to heat up, whether they are in direct contact with the sun or not.
• A white roof or road will actually reflect the sun's rays back into space, keeping the atmosphere cooler.

The panel of economists assembled by the Copenhagen Consensus, is headed by Bjorn Lomborg, a Danish author who is seeking non-conventional responses to the threat of climate change.

The five-member panel, which includes three Nobel laureates in economics, ranked fifteen climate-change remedies, from reengineering clouds to a carbon tax, in order of how much bang they’d offer for the buck. “Marine cloud whitening” came out on top.

The panel scrutinized 21 ground-breaking research papers by top climate economists that analysed the costs and benefits of different responses to global warming, ranging from a focus on black carbon mitigation to climate engineering and varying levels of carbon taxes. Based on an analysis of the new research, they created a prioritised list that outlines the best and worst ways to respond to climate change.

The group concluded that the most effective use of resources would be to invest immediately in researching marine cloud whitening technology (where boats spray seawater droplets into clouds above the sea to make them reflect more sunlight back into space, reducing warming).

Nobel Laureate Thomas Schelling said, “We found that climate engineering has great promise. Even if one approaches it from a skeptical viewpoint, it is important to invest in research to identify the limitations and risks of this technology sooner rather than later.”