Although Bhutan's natural heritage is still largely intact, the government has said that it cannot be taken for granted and that conservation of the natural environment must be considered one of the challenges that will need to be addressed in the years ahead. Nearly 56.3% of all Bhutanese are involved with agriculture, forestry or conservation. The government aims to promote conservation as part of its plan to target Gross National Happiness. It currently has net negative greenhouse gas emissions because the small amount of pollution it creates is absorbed by the forests that cover most of the country. While the entire country collectively produces of carbon dioxide a year, the immense forest covering 72% of the country acts as a carbon sink, absorbing more than four million tons of carbon dioxide every year. Bhutan had a 2018 Forest Landscape Integrity Index mean score of 8.85/10, ranking it 16th globally out of 172 countries.