The resulting hotter, drier summers in countries like Greece could mean forests are more frequently brought to the tinder-box conditions which allowed fires to spread so devastatingly.
Greek Foreign Minister Dora Bakoyanni said the summer's devastating floods in Britain and the worst fires in Greek memory demonstrated climate change was already happening.
"From that moment everyone understood that the phenomena caused by climatic change need to be confronted with much more coordination and speed from the EU," she told a news conference.
Scientists said it was too early to judge how much C02 was released by the Greek fires which are the most intense in Europe in at least a decade and have killed 63 people.
If the trees grow back, they will eventually reabsorb the CO2. "If not, the fires will have contributed to greenhouse gas emissions," said Earl Saxon of the Geneva-based World Conservation Union (IUCN).
Bakoyanni tried to allay fears that the scorched land would be used for building. "We are determined that not the smallest piece of land will not be reforested. Nobody will build on burnt land," she said.
Any net loss of CO2 would not count against Greece's legal obligation to control greenhouse gas emissions.
Under the Kyoto Protocol, Greece, was allowed to increase its emissions by 25 percent over 1990 levels. Non man-made sources, such as wildfires do not count.
The IUCN's Saxon said forests have a natural cycle of fires and regrowth but that global warming could upset the balance. If hotter and drier summers mean more frequent forest fires, that could well mean a net emission of CO2.
"If they become more frequent, then vegetation doesn't have time to grow back and the net effect is that you lose more carbon from the eco-system than the eco-system can recapture before the next fire."
