Back in December 2015 the world congratulated itself on the historic agreement reach in Paris to limit global warming to below 1.5°C.
The COP21 deal was momentous, exceeding expectations of what was achievable and striking a level of ambition that confounded the critics. It laid down the first marker towards a more sustainable future, one in which future generations should be protected from the worst excesses of climate change.
For years, the EU has been a leader on tackling climate change. Though its environmental and climate commitments had come under increasing scrutiny, the pivotal role it played in Paris, standing firm on red lines and forming coalitions across the world, was crucial in securing the final deal.
The UK has undoubtedly played its part in this. For many years it has been one of the international standard bearers for climate change action. David and Ed Miliband passed into law the world's first Climate Change Act, while Gordon Brown was the leading figure behind the creation of the UN's Global Climate Fund, which helps the poorest countries in the world protect their people from the increasing perils of rising sea levels and extreme weather.
But just as Britain has long been a force for progressive climate policy, its pending withdrawal casts a cloud of uncertainty over the whole Paris deal.
When the deal was signed back in December, it was signed collectively by the EU submitted its plan on the basis of what 28 member states had agreed.
By signing the deal collectively, the EU became the most important political entity that could achieve the necessary reductions in greenhouse gases and carbon emissions to achieve the 1.5°C target, throwing momentum behind the process and playing a key role in the striking a final agreement.
However, the removal of one of those member states would seriously undermine the EU's commitments and spell real danger for the historic deal made in Paris.
Cue Brexit. Given Britain is the second largest economy inside the EU its looming withdrawal, helped little by the ludicrous decision to abolish the Department for Energy and Climate Change, has created a great deal of uncertainty.
Christiana Figueres, the former executive secretary of the UNFCCC, the UN body responsible for overseeing the process, has argued the UK's decision to leave the EU will require aspects of the Paris deal 'to be re-written'.
The EU will have the very tricky task of recalibrating its commitments across remaining states. More serious though, is the danger of further delay.
At a time where Pacific islands are already starting to sink into the rising sea - when populist, climate change sceptics like Donald Trump are running on platforms promising to overturn the Paris agreement - every day makes it more urgent, and more difficult, to limit global warming to non-catastrophic levels.
This week I joined sixteen colleagues from across the European Parliament's Environment Committee and Industry, Research and Energy Committee in writing to the European Commission with ten key requests for the upcoming proposals on the EU's energy and climate framework.
We feel this is a vital time for the Commission to ensure the EU's policies are up to scratch and properly reflect the possible fallout from Brexit. Not only will the Commission need to step up its efforts to ensure the agreement in Paris is ratified as soon as possible, it also needs to set out how the EU will hit the targets it sets out.
Britain's decision to leave the EU and its impact on the Paris agreement remains unknown. But impending Brexit has certainly created far more questions than answers when it comes to tackling climate change. We must do all we can to ensure there is a positive answer to them.