China and India have planted so many trees that the world is now greener than it was 20 years ago, a counterintuitive new study claims. The superpowers are two of the world's top three most polluting nations and the increase in foliage is mostly a result of 'ambitious tree planting programs'. NASA research discovered there is five per cent more greenery every year compared to the 2000s, resulting in more than two million square miles of extra greenery - the equivalent of more than the Amazon rainforest. Chi Chen from Boston University, who led the research, said China and India 'account for one-third of the greening, but contain only 9 percent of the planet's land area covered in vegetation'. The greening on the planet was first detected in the mid-1990s and from images provided by NASA'S MODIS tool which orbits the Earth on two satellites and provides high resolution images of Earth's surface. China is responsible for a quarter of the overall increase in green leaf area but has only 6.6 per cent of all the world's foliage. India has contributed a further 6.8 per cent rise in green leaf area. Scientists say it is important to factor in this latest finding into future climate change prediction models. 'This long-term data lets us dig deeper,' said Rama Nemani, a research scientist at NASA's Ames Research Center, and a co-author of the work. The research was published in the journal Nature Sustainability.