Officials, experts and activists from over 190 countries have gathered at Lima for a conference to discuss -and hopefully finalize - an agreement on cutting greenhouse gas emissions. The official meeting, called the Conference of Parties (COP), is an annual affair held under the aegis of the UN. This is the 20th such conference. Countries are represented by ministerial level or higher delegations. They'll discuss the status of countrywise emissions, and proposals for cutting them over time. Experts will advise participants on how emissions can be cut.Hundreds of activists are also there highlighting the dangers of not reaching an agreement.Indications are that the Lima meeting will do the groundwork and the agreement will be made -or not - in next year's Paris COP. All countries are one on reaching an agreement by 2015, which will become applicable by 2020.

Why is a global pact on climate change necessary?

Emissions of carbon dioxide and other gases that trap solar heat and cause climate L change are continuing without significant T change leading to in creasing extreme weather events such as cold spells, heat waves, floods, droughts. Scientists predict that the situation will get worse if nothing is done to stop runaway emis sions. Everybody agrees that global temperature shouldn't be allowed to rise more than 2°C above the pre-industrial average by 2100. But the emission rate is such that this target is now considered unach ievable. Countries have been squabbling over how much emission each of them can cut.

They're trying to strike a balance between short term national interest and long-term global in terest. The whole world must agree to work together - only a few countries cutting emissions won't help.

What are the chances of an agreement?

After countries failed to reach an agreement in Copenhagen in 2009, there was worldwide pessimism that a common deal would never emerge. But the Lima conference has seen rekindling of hope as many major GHGs emitters are open to committing to emission cuts. Last month, US pledged to cut emissions to 26-28% below 2005 levels by 2025 in a deal with China. Earlier in October, EU agreed to binding 40% cuts by 2030 from 1990 levels.The focus will be on big emitters like US, China, EU, India, Brazil, Japan, Russia and Indonesia. There's fear that separate commitments like the US-China deal will force countries like India to commit to unfair cuts because India's per capita emissions are way behind advanced countries.