ExxonMobil, the largest American oil group, has written to the Trump administration urging it to keep the US in the Paris climate accord agreed at the end of 2015. In a letter to President Donald Trump’s special assistant for international energy and the environment, Exxon argues that the Paris accord is “an effective framework for addressing the risks of climate change”.  The letter was sent last week, but has emerged as Mr Trump is preparing to announce executive orders beginning a rollback several of Barack Obama’s climate policies, while leaving the question of Paris open. Trump administration officials have said a decision on participation in Paris is still “under discussion”, and have been soliciting views from US energy companies.  Exxon argues in its letter that there are several reasons for the US to stay in the Paris accord, including the opportunity to support greater use of natural gas, which creates lower carbon dioxide emissions than coal when burnt for power generation.  Several other large international oil companies, particularly in Europe, have also backed action to address climate change that could benefit them by boosting demand for gas.