If you take any interest in green issues, you're bound to have noticed the recent spate of articles about global warming.

On 19th September, Ananova reported on NASA-funded research which involved constructing alternative climate models based on differing levels of greenhouse gas emissions. It found that temperatures may increase by one or two degrees Celsius if no action is taken to reduce emissions, but that if the growth rate of carbon dioxide levels off or drops and pollutant emissions are reduced, temperatures may rise by only 0.75 degrees Celsius.

NASA were also involved (along with America's National Oceanic and Atmospheric Administration) in research into the ozone hole over Antarctica, as reported on 1st October by Ananova. NOAA and NASA scientists have found the ozone hole to be markedly smaller this year than in the past few years and that it had split in two. The hole (which is actually an area of thinner than normal ozone) was measured at six million square miles in September, three million square miles less than expected at this time of year.

While the researchers attributed the improvement to warmer than normal temperatures around the edge of the polar vortex (the circular wind pattern that forms annually in the stratosphere over Antarctica), experts in New Zealand and Australia believe that falling levels of CFCs in the environment (see Ananova story on 18th September) have helped to repair the damage.

If that news is encouraging, continuing warnings about the potential impacts of global warming are sobering.

On 29th September, the Independent reported on a Royal Society study which contradicts the widespread belief that British butterflies will prosper in a warmer climate.

On the same day, Ananova covered a British Antarctic Survey report in which the disappearance of Antarctic seabirds such as the Emperor penguin, Adelie penguin, and the snow petrel was linked to global warming. On 10th September, Ananova reported that thousands of other Antarctic species, from sea spiders, molluscs, worms to seals and whales also face an uncertain future as sea temperatures rise.

Predictions that coral reefs around the world face near exinction are old news. BBC News reported on comments by Dr Rupert Ormond of the University of Glasgow in September 2001: "I find it very hard to avoid the conclusion that it is inevitable that most coral in almost all coral areas will be lost," he told journalists at the British Association Festival of Science in Glasgow.

In July 2002 BBC News reported on a United Nations report that warns that Africa is facing irreparable damage to its environment because of global warming and other problems. Over the next 30 years, growing populations, wars, climate change and the introduction of alien plants and animal species will increase poverty, destroy the environment and spread disease.

In addition to the damage caused to the often fragile environments across the continent by global warming, rising sea levels are threatening the Gulf of Guinea, Senegal, Egypt, The Gambia, the eastern African coast as well as the western Indian Ocean islands.

The world's politicians had an opportunity to form a plan to deal with these problems when they attended the Johannesburg world summit on sustainable development between August 26 and September 4 2002 (see the Guardian's report). The well-publicised compromises made in order to appease the USA and some oil-producing nations left many people dismayed, although not entirely surprised.

However, the weakness of the final statement spurred 30 countries to go it alone on green energy. Support came from all 15 EU states, Norway, Iceland, Switzerland, Poland, Hungary, the Czech Republic, Romania and Slovakia, Brazil, Argentina, Uganda, Mexico and other Latin American states, plus some Caribbean and Pacific islands.

Leaders from these countries pledged to go further than the summit declaration on increasing the share of renewable energy as part of the global energy supply. The countries concerned agreed to a regular review of progress, on the basis of clear and ambitious targets at a national, regional and "hopefully at a global level".

To finish on more positive recent news, Ananova reported that chemists in the US have developed an easy way of making hydrogen from plant matter (offering an alternative to more polluting fuels), that a Norwegian company had pumped more than four million tonnes of carbon dioxide into porous sand beneath the sea bed to keep it from the atmosphere and that Brazil had created the world's largest tropical forest park.

What are your views on our politicians' inability to reach long-lasting and meaningful agreements on global warming? Use our comments page to have your say.