Today is Earth Day and Joe Biden, the US President, has invited leaders of 40 countries to come together for a two day zoom conference to discuss the climate emergency. Seventeen of the countries invited are responsible for 80% of carbon emissions in the world. Biden is expected to announce his commitment to halve the carbon emissions of the USA by the end of this decade. And he will be exhorting invitees, which include President Ji of China and President Putin of Russia, to follow his example. Why is this important for us health professionals?

Over the past 30 years we have been advocating for action to tackle the greatest health emergency humanity has ever faced—the ever worsening environmental damage caused both directly and indirectly by fossil fuels.

Many medical journals have carried articles showing how the requisite actions to reduce carbon emissions can have immediate health benefit, offering, in the jargon of the day, a “win win.” Over the past 15 years a number of coalitions of health professionals have come together to clarify the health benefits of action and to increase the leverage we can collectively exercise on decision makers. Prominent among these coalitions are the Global Climate and Health Alliance (GCHA), the World Organisation of Family Doctors (WONCA) and the UK Health Alliance on Climate Change (UKHACC).

There have been notable examples of health professional leadership, such as the Lancet Countdown project and the commitment from the NHS to get to carbon net zero by 2040. In addition, to give us all at least a chance of stabilising the global temperature at no greater the 1.5 degrees above the pre-industrial average, WONCA ,the GCHA, and the UKHACC have articulated the absolute necessity of the globe getting to net zero by 2040, and doing so in an equitable way guided by the framework of contraction and convergence. This is the best presently available framework for capping global carbon emissions and distributing the remaining allowance in an equitable way, so meeting the IPCC requirements of precaution and equity.

But the world is still on course for catastrophe: even with resurgent US action, countries have cut emissions too slowly and are failing to sign up to stringent emissions into the future, something which Biden is seeking to address. Current plans put us on course for a catastrophic 3C increase in warming by the end of the century.

So brave and rapid leadership at the highest level is clearly now required. President Biden’s initiative is an example of such leadership, and is founded on the unprecedented steps he is taking at home, including his proposed $2 trillion stimulus plan. This will usher in an era of public investment unseen since government action to rebuild after the Great Depression and WWII, and is a proportionate response to this planetary emergency. His leadership should attract the support of the health professional community. But the health community should also challenge it, being clear on the risks to health of false promises and stunted ambition. In light of covid-19 and the upcoming UN climate change conference (COP26) in the UK in November, this community has a particularly important role that it can, and should, play. So many of us have been on the frontline of the covid-19 crisis and we should use the larger public role—and the respect and trust revealed in survey after survey—to stiffen the resolve of world leaders in seeing off a far-worse crisis.

This should be done in two ways. Firstly, the 1.5C target must remain the abiding focus. Beyond this, we heighten the risks of triggering unmanageable, runaway change in the natural world which will burden societies with compounding destabilisation, bringing with it huge costs in terms of adaptation to heat extremes, lost harvests, and forced displacement.

This would be a dangerous, unstable world, in which we have squandered the “win-win” of realising more sustainable and healthy societies and in which the burden of mortality and morbidity is both extreme and unjust, falling on those who are least responsible for the problem and most vulnerable to its effects. The covid-19 crisis is a warning from the future in this regard. This is why UKHACC, WONCA, and GCHA have called for global emissions to be reduced to zero by 2040 and in an equitable way. A key test for leaders over this crucial year is whether they hide behind long term targets, instead of setting goals for 2025 or 2030, as well as 2050, and whether they propose credible plans and levels of investment to meet these targets, which don’t bet the future on the roll out of vast carbon-sucking technologies.

Secondly, countries with the greatest responsibility for carbon emissions—mostly high income countries—must transfer funds to countries that are most vulnerable to the impacts of the climate crisis, enabling them to adapt and prepare as well as reduce their emissions. As part of the Paris Agreement, wealthy countries agreed to provide $100bn in support for more vulnerable nations by 2020. They failed to do so and so the success of COP26 largely depends on a credible commitment to following through on this promise. Covid-19 provides parallels here, as well. Vaccine nationalism and a failure to adequately support the covid response in poorer nations, such as through debt relief, is a self-defeating folly: we are only as strong as our weakest parts. The same principle goes for the climate emergency. So healthcare professionals can and should use their voice to ask whether leaders are doing all they can to help the most vulnerable across the world, not just as a moral imperative, but as a practical strategy for shared survival.

This is a crucial year. As health professionals continue to battle the virus, we should use our voice to focus leaders’ minds on avoiding the next, worse health crisis—and to realise a better world in the process. Applauding President Biden’s brave initiative is a first step.

Laurie Laybourn-Langton, associate fellow IPPR.

Robin Stott, executive member, UK Health Alliance on Climate Change.

Competing interests: none declared.