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Scientists are frantically looking for new ways to combat global warming.

And now a team has created a sponge that absorbs carbon dioxide, which many scientists say plays a key role in heating up our planet.

They believe that the polymer – a large molecule used in plastics - could bridge the gap between the use of fossil fuels and new energy sources such as hydrogen.

Scientists have created a sponge that absorbs carbon dioxide. They believe that the absorbent material could bridge the gap between the use of fossil fuels and new energy sources such as hydrogen and could be easily integrated into smokestacks in the future (illustrated)

The material - a relative of the plastics used in food containers - could be integrated into power plant smokestacks in the future.

Speaking at the 248th National Meeting & Exposition of the American Chemical Society (ACS), Dr Andrew Cooper of Liverpool University said: 'The key point is that this polymer is stable, it's cheap and it adsorbs CO2 extremely well.

'It's geared toward function in a real-world environment. In a future landscape where fuel-cell technology is used, this adsorbent could work toward zero-emission technology.'

Carbon dioxide adsorbents are most commonly used to remove the greenhouse gas pollutant from smokestacks at power plants where fossil fuels like coal or gas are burned.

But Dr Cooper says that the new material would be a part of an emerging technology called an integrated gasification combined cycle (IGCC), which can convert fossil fuels into hydrogen gas.

Many scientists think that hydrogen has great potential for use in fuel-cell cars and electricity generation because it produces almost no pollution.

Carbon dioxide adsorbents are most commonly used to remove the greenhouse gas pollutant from smokestacks (pictured) at power plants where fossil fuels like coal or gas are burned. But Dr Cooper says that the new material would be a part of an emerging technology which can convert fossil fuels into hydrogen gas

IGCC is a bridging technology that is intended to jump-start the transition to hydrogen fuel, while still using the existing fossil-fuel infrastructure.

The IGCC process yields a mixture of hydrogen and carbon dioxide that must be separated.

Dr Cooper says that the sponge works best under the high pressures necessary for the IGCC process.

Just like a kitchen sponge swells when it takes on water, the adsorbent swells slightly when it soaks up carbon dioxide in the tiny spaces between its molecules.

When the pressure drops the adsorbent polymer deflates and releases the gas, which they can then collect for storage or convert into useful carbon compounds.

The material, which is a brown, sand-like powder, is made by linking together many small carbon-based molecules into a network.

One advantage of using polymers is that they tend to be very stable. The material can even withstand being boiled in acid, proving it should tolerate the harsh conditions in power plants where carbon dioxide adsorbents are needed.

Another advantage of the new polymer is its ability to adsorb carbon dioxide without taking on water vapour, which can clog up other materials and make them less effective.  Its low cost also makes the sponge polymer attractive.

'Compared to many other adsorbents, they're cheap,' Dr Cooper said, who explained that the carbon molecules they are made from are inexpensive.

'In principle, they're highly reusable and have long lifetimes because they're very robust,' he added.

Dr Cooper believes that it would be relatively simple to embed the spongy polymers in the kinds of membranes already being evaluated to remove carbon dioxide from power plant exhaust.