Theewaterskloof Dam on the Sonderend River, a major water source for Cape Town. Water levels have dropped to very low levels in recent years. Photo: RapidEye / Getty Images

At the time when the historic Paris Agreement was reached five years ago, we were among a group of researchers investigating the topic of “high-end” climate change, defined as global average temperature changes exceeding 2 degrees Celsius compared to pre-industrial times. We were looking into the possibility that the people of the world might need to adapt to face that kind of reality.

This is a topic that, understandably, makes people uncomfortable. No one wants to think about this possibility – or to address just how the world would do to adapt.

In the early days of the climate movement, well before the Paris Agreement, adaptation to climate change was itself something of a taboo subject. The fear then was that adaptation only siphoned away attention, effort and money from the mitigation goal. This was the “ounce of prevention is worth a pound of cure” point of view.

Climate change itself has since changed this dynamic. The need to adapt is now as real as the need to mitigate as glaciers retreat , hurricanes and tropical storms reach record numbers , and the world yet again experiences one of its warmest years in history . Today, it is recognized that we are committed to a certain level of warming, whatever we do.

“Dangerous” climate change – that is, the levels that we hope to prevent – and adaptation to it – that is, the actions that we hope will not be necessary – are the antithesis of the Paris Agreement.

Mitigation and adaptation are intertwined

No science suggests that one mission is more important than the other. No science suggests that the two missions compete against one another.

A global policy cannot be built on an idea that just one goal matters. The Paris Agreement itself recognized this when it established a global adaptation goal of “enhancing adaptive capacity, strengthening resilience and reducing vulnerability to climate change”. This recognizes that sensible people can – and must – do more than one thing at a time.

The IPCC Special Report on the impacts of global warming of 1.5 °C, published late 2018, showed that impacts at 2 degrees are likely to be much more severe than those at 1.5 degrees. Yet, the 2020 UNEP Emissions Gap report clearly and dramatically shows that the world is not on a pathway to 1.5, or to 2, but to 3.2 or 3.5 degrees by the end of the century. In the absence of any policies, global warming could reach 4.1 – 4.8 degrees above pre-industrial levels by the end of the century, the Climate Action Tracker shows. This is why the topic of adaptation under high-end climate change is important. Examining it is not conceding defeat. It is being prudent.

Precautions are warranted

Clearly, ambitious mitigation is needed – and the Paris Agreement is the foundation for achieving such greater ambition. But we also need to take precautions in case the temperature goal isn’t met.

This, however, is not part of the Paris Agreement. The global goal on adaptation is defined as adequate adaptation response in the context of the temperature goal. The Paris Agreement effectively draws a line between adaptation consistent with this goal, and adaptation considering consequences of dangerous climate change of more than 2 degrees.

We can and must view mitigation and adaptation as intertwined and urgent issues. No matter how much we do on mitigation, we cannot exclude surprises beyond the most likely scenario. Policy is uncertain. So are the world’s natural systems – and the pace of technological advance. The COVID-19 pandemic underscores the ability of events to upend plans.

This is a practical matter. To borrow the adage of Robert Baden-Powell, who founded the worldwide Scout movement, “Be prepared.” When asked, “Prepared for what?”, his response was clear:  “Why, for any old thing.”

Adaptation experts are growing more concerned

Our own work in the wake of the Paris Agreement underscores the importance of taking on the issue of adaptation to climate change – even extreme levels of climate change – with the urgency it deserves.

We have twice surveyed the perceptions and practices about the dangerous climate change levels among those who work at the forefront of climate change adaptation agenda. In 2016 and again in 2018, we put questions to participants in the biennial Adaptation Futures conference, the largest gatherings of climate adaptation experts. Our findings are sobering. Most strikingly, our surveys showed that a majority disagreed that the Paris Agreement has reduced the possibility of the world reaching dangerous levels of climate change. Moreover, participants’ pessimism grew over the period, with the share of experts holding a negative view growing from 42% in 2016 to 60% in 2018.

Moreover, roughly two-thirds of these experts are considering high-end climate change in their work all the time. Even as they attempt to do this, a majority of participants also thought that it was difficult to find information on impacts and tools for decision-making under dangerous levels of climate change. These views have not changed between 2016 and 2018, showing that there has been no progress on this front.

These findings are worrying because such information is already needed for planning responses to climate risks. An additional problem, as detailed in the Working Group II contribution to the IPCC Fifth Assessment Report , is that the greater the temperature increase, the more likely it is that adaptation reaches limits to its effectiveness. Strategies that have worked in the past for managing moderate change are not always going to be successful as we face greater change.

Preparing for an unpredictable future

We need to invest more in understanding how best to adapt to strong, impacts of climate change, no matter what level of temperature rise the world eventually experiences. This effort starts with greater financial support. Adaptation is woefully underfunded. Estimates by UNEP show that adaptation finance needs will range from 140 billion USD to 300 billion USD by 2030; thus far, available finance for adaptation is a fraction of that – roughly 23 billion USD. Though climate finance budgets have ramped up considerably since the Paris Agreement, questions remain about what “counts” as climate finance; and there are questions about how to make the agendas “just” – in terms of whose priorities take precedence in shaping funding rules.

Moreover, we need greater understanding of what works best to achieve effective adaptation so that the investments made have a meaningful impact. We are now undertaking work to examine the effectiveness of adaptation funds. Current research is looking at what kinds of funding and what characteristics play a role in adaptation outcomes. Which financing mechanisms work? Which fail? Or which have no impact at all?

We have not repeated our survey during this cataclysmic year. Perhaps if we were to survey the same group of adaptation experts now, they would feel more optimistic. More positive developments came at the end of 2019 when the Paris Rulebook, the guidelines needed to help countries implement the Paris Agreement, was largely agreed. In the wake of the November elections, the United States is poised to rejoin the Paris Agreement under a new administration. Many countries announced more ambitious climate plans at the recent online Climate Ambition Summit . And, of course, scientific knowledge continues to improve.

But the insights of experts nonetheless suggest that more is needed – not just to achieve the temperature goal of the Paris Agreement, but to ramp up the scale and effectiveness of adaptation action around the world. Many experts believe that such action is needed to prepare for warming that is likely, and for even greater warming that is less likely but cannot be excluded. Five years after Paris, this seems more important than ever. Because, as 2020 has profoundly underscored, any old thing could happen.