Create a commission with members of all the main political parties to set ambitious targets and agree policies to combat climate change and ensure the UK meets and exceeds the agreements at Paris. These should be made legally binding, with cross-party oversight for accountability.
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The challenges of climate change mean that what must often need to be done is very difficult because of the political ramifications to any given party. Therefore ambitious or disruptive policy is difficult to embed for fear of displeasing potential voters. Collectively agreeing a set of legally binding outcomes across parties, that any party in government is responsible for delivering, and overseen by all parties, removes the political barriers to effective action.