The climate summit in Paris that ended on December 12th was always going to be an important occasion. For years, it has been seen as the best chance to agree a global deal to tackle climate change since the underwhelming talks held in Copenhagen in 2009. But following the terrorist attacks in Paris on November 13th, the talks took a different direction. They became a symbol of global solidarity with the French people and highlighted that the recent terrible events wouldn’t impede efforts to tackle our climate’s long-term future.

And whilst the Paris talks didn’t deliver on all fronts and have not as such provided a guarantee that we will avoid the worst impacts of climate change, they have produced the most promising international climate agreement in years—and, critically, one designed to be strengthened in the years to come.

The fact that over 180 countries have made initial commitments to reduce their carbon emissions, that there is a review clause that will encourage countries to increase their pledges in the near future, and that developing countries will now receive more financial support to adapt to and tackle climate change are important steps forward. And the fact that close to 150 world leaders gathered in Paris to mark the start of the talks, coupled with unprecedented and positive levels of business engagement, is testament to the growing momentum behind global climate policy.

As an organisation that has major corporate members from across the economy, the Aldersgate Group sees this deal as a very positive step forward for both the environment and the economy. As The Economist Intelligence Unit (EIU) pointed out in its recent report on The Cost of Inaction, climate change, if left unchecked, presents a considerable risk to the economy. Using private individual discount rates, The EIU's forecasts predict climate change to cause average losses to manageable assets globally of US$4.2tn in net present value terms out to 2100. This is equivalent to Japan’s GDP. Losses would be significantly worse in the case of high temperature increases and when considered from the perspective of governments, which put greater value on long-term costs.

But as the Global Commission on the Economy and Climate mentioned at a recent event in Paris hosted by Aviva and the British Embassy, we now have the evidence that countries at all levels of development can tackle climate change whilst supporting economic growth. And with some US$90tn to be invested over the next 15 years in the world’s urban, agricultural and energy infrastructure, governments have the opportunity to set out the policies that will ensure this investment is overwhelmingly low-carbon, with all the benefits that this would bring.

Translating international success into ambitious domestic policy

To make Paris a lasting success, it’ll be important that the key agreements on issues such as financial support and the increase of emission-reduction pledges are further developed in the months and years ahead. But an international deal can only deliver change if countries also practice what they preach at home through suitably ambitious national policies.

When it comes to the UK, we should give credit to its government and its positive and impactful international climate policy over the years through the work of the Foreign & Commonwealth Office, the Department of Energy & Climate Change (DECC) and the Prime Minister's Office. The UK government has played an important role in delivering the results in Paris, demonstrating how its policy priorities outstretch beyond the UK itself. But when it comes to domestic energy policy, the picture is far less positive.

A suite of rather incoherent policy decisions in recent weeks ranging from low ambition on energy efficiency and patchy support for renewables to the scrapping of funding for carbon capture and storage technology have left the UK in the awkward situation that it is now no longer on track for meeting its own climate targets (known as "carbon budgets"), despite the positive role it has played internationally for years. The fact that many of these decisions appear to have been directed by the Treasury (the UK government's economic and finance ministry), rather than the DECC, is adding to the confusion.

With the positive outcome it has helped engineer in Paris, the UK government must now use this momentum in 2016 to deliver once and for all a coherent plan to meet its carbon budgets in a way that is timely, cost-effective and generates supply-chain benefits for the UK. As the DECC’s Lord Bourne said at the British Embassy event last week, rapid action to cut emissions isn’t only essential to protect those developing countries that are most vulnerable to climate change, it also makes profound economic sense.

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the views of The Economist Intelligence Unit Limited (EIU) or any other member of The Economist Group. The Economist Group (including the EIU) cannot accept any responsibility or liability for reliance by any person on this article or any of the information, opinions or conclusions set out in the article.