Воткнуть пропущенное слово.1. Natural Factors ... as wildfires sometimes contribute to

Воткнуть пропущенное слово.
1. Natural Factors ... as wildfires sometimes contribute to deforestation, too.
2. When forests are cut down or burnt, most of these gases stay in the Earths atmosphere, ... speeds up global warming.
3. In fact, in the next 24 hours, deforeststion will be responsible for the release of as much CO2 into the atmosphere as that form as ... flights as it takes to carry 8 million people from London to NY!