The IPCC’s report on global warming of 1.5˚C spells out the urgency of action

IIED director Andrew Norton looks at the new report on climate change.

Blog by
8 October 2018

Andrew Norton is the director of IIED

Citizens wade through a flooded road in Bandung City

The long-awaited special report from the Inter-Governmental Panel on Climate Change (IPCC) on the impacts of global warming of 1.5˚C above pre-industrial levels was released this morning – and the message is stark: if urgent action is not taken now the consequences will be appalling.

The world is now at 1˚C of warming and we are already seeing profound impacts in terms of extreme weather and damage to ecosystems on a global scale. That should focus attention on the seriousness of the challenge. The report says that without urgent action we could pass 1.5˚C as early as 2030.

The authors have said that the differences between 1.5˚ and the weaker Paris Agreement target of 2˚C came as a revelation. These differences include: 

  • An extra 10cm of sea level rise by 2100, exposing an extra ten million people to risks including displacement
  • The loss of virtually all coral reefs and massive damage to all coastal ecosystems – with huge implications for the estimated 300 million people worldwide who depend on fisheries for their livelihoods, the vast majority in poorer countries
  • Severe damage to ecosystems on land, with many species forced into much smaller areas, and worse damage from forest fires and invasive species, and
  • At 2˚C, 50% more of the world’s people will be exposed to water stress.

In short, limiting warming to 1.5˚C will reduce challenging impacts to both human society and the natural world, making progress across the full range of UN Sustainable Development Goals considerably easier.

And there is another subtext that should be clear to everyone: the damage, loss and risks that arise from the difference between 1.5˚C and 2˚C do not fall equally. They fall more heavily on the poorest and most vulnerable people, communities and countries in the world – those who have done least to create the problem.

The picture presented by the report is, in fact, quite conservative. The more complex risks arising from climate change – including, for example,  population displacement – are not directly considered.

And the report does not reference the possibility that stabilising the world’s temperature at 2˚C may not be possible, due to the multiple possible ‘tipping points’ that might be triggered at around that point.

These are self-reinforcing feedback mechanisms (for example the melting of permafrost releasing greenhouse gases trapped below) that once started, might well send the planet towards a ‘hothouse’ state. So, the question of limiting warming to 1.5˚C is even more urgent and critical than the report suggests.

The good news is that staying under 1.5˚C is still technically feasible, and some progress has been made. But rapid and radical action will be needed to effect the necessary changes in the management of land, energy, buildings, transport and cities. The report indicates that global net human-caused emissions will need to fall by about 45% from 2010 levels by 2030, reaching ‘net zero’ by 2050.

"Pathways limiting global warming to 1.5°C with no or limited overshoot would require rapid and far-reaching transitions in energy, land, urban and infrastructure (including transport and buildings), and industrial systems (high confidence)" - IPCC report

All the pathways outlined in the report for limiting warming to 1.5˚C rely on rapid cuts in greenhouse gas emissions, combined with efforts to remove carbon dioxide from the atmosphere at a greater rate than the earth’s ‘carbon sinks’ (mostly forests and oceans) currently do. The faster emissions are cut, the less carbon dioxide will need to be removed.

Critically, rapid emissions cuts would reduce the need to depend on technologies that are both unproven at scale, and likely to be greatly damaging in human terms – such as ‘bio-energy with carbon capture and storage’ (BECCS). In short, ‘nature-based solutions’ (mostly trees) may still be enough on their own if emissions cuts are sufficiently fast. An increased focus on the question of how to remove more carbon dioxide from the atmosphere is going to be one of the legacies of this report, for sure.

Global political progress over the last two years has been weak. After a couple of years of stability, global greenhouse gas emissions have started to rise again – even in places (such as the European Union and China) where we would hope for leadership.  

President Trump’s announced intention to withdraw the US from the Paris Agreement has reduced global political momentum. If the far right candidate in Brazil’s forthcoming election, Jair Bolsonaro, wins, then his country may follow Trump’s hugely damaging example.

The global climate community has been saying that action is urgent for a long time but we do not yet have the momentum for the scale of change that we need. The big question is ‘how can we make sure that this time is different?’

Learning from climate leaders

The first answer lies in learning from the places that are showing leadership.

Cities will be a key location. Some cities, like Durban, are leading the way in driving change and influencing national and global politics. Other sub-national governments can also give genuinely global leadership, as the example of the US state of California has shown.

The leadership shown by some of the world’s less powerful countries (including small island states and the least developed countries (LDCs) was decisive in getting agreement in Paris to the 1.5˚C goal. 

IIED has worked for many years to support the LDCs in the remarkable work they have done to highlight the human impacts of climate change, and advocate for more urgency and ambition of action. Richer countries need to show their support – both by accelerating their actions to reduce emissions, and by ensuring that the Paris pledges to provide support to the poorest countries for climate action are actually met.

A road with a factory and dazzling sunlight in the distance

Change must happen

The second answer is to make it ever clearer that radical changes to our production and consumption systems are inevitable. They must happen at some point.

The IPCC report makes it clear that there will be no ‘magic bullet’ solutions. The economies, businesses and societies that are at the forefront of change will benefit from their far-sightedness.

Those that do not will not be first, but last. And they may do a great deal of damage along the way.

About the author

Andrew Norton ( is the director of IIED