As in the run-up to any Group of Eight summit, talk is swirling about the promises the leaders of the world's richest nations might make when they meet in Italy this week.

Aid groups, climate scientists and developing countries say the signals on curbing global warming are promising but don't go far enough. In particular, they say any commitments to curb climate change will lack focus unless they include short-term targets for reducing carbon emissions by 2020.

Progress on this is regarded as highly unlikely at the July 8-10 summit in the quake-hit town of L'Aquila.

"It is really quite hopeful that the G8 is even at the level of what it's discussing now, but in terms of the most vulnerable (people) and in terms of the science it probably still isn't enough," said Diana Liverman, a scientist and member of the new National Academy of Sciences Committee on America's Climate Choices, which is advising the U.S. government on responses to climate change.

"The question for the G8 is can they come together and talk about a 2020 commitment? We must make some commitments by 2020, otherwise we just can't see the emission reductions in the scenarios that are going to start bringing down the risks (of climate change)," Liverman told AlertNet.

Alongside the G8 meeting, there will also be a gathering of the Major Economies Forum (MEF) - 17 countries that account for around 80 percent of global carbon emissions including China, India and Brazil. So what are the main possibilities being floated on climate change for the two key meetings this week, and how are they viewed by aid and climate experts?

TWO DEGREE LIMIT ON GLOBAL WARMING:

It has been widely reported that G8 nations could agree to limit global warming to no more than two degrees Celsius - seen by the European Union and some developing countries as the threshold beyond which climate change will reach dangerous levels. So far, Washington has not backed a limit on temperature increases, but officials involved in preparing the summit say that's about to change.

Saleemul Huq, head of the climate change group at the London-based International Institute for Environment and Development (IIED), says G8 endorsement would be a step forward but would not let developing countries off the hook. "Even 2 degrees does not mean there will not be significant impacts, particularly in the more vulnerable developing countries. Some of (them) have been asking for (a limit of) 1.5 degrees," he said.

Quamrul Chowdhury, a member of the Bangladesh negotiating team at the U.N. climate talks, said anything less ambitious than keeping global warming to below 2 degrees would threaten the lives and livelihoods of millions of the poorest people in the least-developed countries (LDCs).

"It would mean for Bangladesh and other LDCs more frequent and intense flooding, cyclones and droughts," he told AlertNet. "No adaptation (to climate change) would work, whatever money our G8 brothers would throw at tens of millions of drowning people." Liverman argued for the need to introduce binding obligations or outline specific steps on how to ensure a 2-degree limit would not be exceeded.

2050 TARGETS FOR EMISSIONS CUTS

G8 leaders may agree that the world should cut greenhouse gas emissions by 50 percent by 2050, with rich nations reducing them by 80 percent, according to the BBC. Last year the G8 outlined a "vision" of halving emissions by 2050, without setting a base year. Developing countries at the Japan summit did not adopt the goal, arguing that the rich first had to set tough 2020 cuts for themselves. Reuters reports that MEF nations in Italy this week will also consider an "aspirational" goal of cutting world greenhouse gas emissions by 50 percent by 2050, according to the draft text of a statement, although it does not mention a base year.

In Huq's view, a G8 goal for cutting emissions by 2050 would be "good as an aspirational target but it's not a functional, operational target." "Really it is too long a time-scale. It's the more short-term targets that really matter," he said.

Aid groups and vulnerable developing countries are calling for emissions cuts of 40 percent or more from 1990 levels by 2020. The European Union has promised to cut emissions by at least 20 percent by 2020 from 1990 levels, and U.S President Barack Obama aims to cut U.S. emissions back to 1990 levels by the same deadline. Japan recently announced a 2020 target equivalent to a cut of just 8 percent from 1990 levels.

"So far if you add up all the proposals from the (developed) countries, they don't really add up to a sufficiently ambitious target," Huq said.

Liverman said it was important to work out the means for meeting any longer-term end. "The more we put off the emissions reductions, we know from the science and the modelling, it is going to increase the risk that we exceeds two degrees or tipping points, but it's also going to make it more costly to do those reductions later," she said.

Among other demands, a group of 22 leading climate scientists called on MEF leaders this week to commit to a global emissions peak by 2020, and on developed countries to set "appropriate intermediate targets" in time for December's key U.N. climate talks in Copenhagen, which are meant to agree a successor pact to the Kyoto Protocol.

FUNDS FOR TACKLING CLIMATE CHANGE

Aid experts say the G8 discussions could touch on how much money rich nations would be willing to provide to help poor countries cope with the impacts of climate change and curb their emissions - although firm pledges are unlikely.

Two weeks ago, British Prime Minister Gordon Brown said rich countries should be prepared to stump up $100 billion per year by 2020, although aid agency Oxfam says the annual sum required is more in the region of $150 billion. The world's least-developed countries want immediate financing of up to $2 billion to pay for planned measures to adapt to the effects of global warming, including droughts, floods and rising seas.

IIED's Huq said that if the G8 were to pledge all - or even part - of this cash, it would go some way towards bridging the trust gap that has emerged over the lack of international funding available to help vulnerable states deal with the consequences of climate change.

Liverman - who wrote the foreword to a new report from Oxfam warning that climate change is already destroying harvests and causing widespread hunger in the world's poorest countries - said an expected G8 pledge to invest billions of dollars in agricultural development to fight food insecurity could help boost resilience to climate change. She said Washington had become more positive towards funding adaptation activities in poor countries. But she argued that any G8 commitments on climate financing must not be taken from existing aid budgets.

"People who are already poor and already vulnerable - they are already dealing with natural disasters, they are already dealing with disease, and climate change brings an extra burden of disease, so it's pretty simple - you need extra money," Liverman said. "There is a risk that, especially with countries that are having trouble with the recession, they will try to do the right thing, but will engage in a little bit of smoke and mirrors."

Reuters AlertNet is not responsible for the content of external websites.