WATER POLITICS

This year we have seen extreme events devastate populations, cause hundreds of millions of dollars of economic losses as well as trigger food insecurity and supply chain shocks all around the world. Not surprising, as we have seen record-breaking warming this year – September even hit 1.75°C of warming above pre-industrial levels, putting us on track for 1.4°C of warming for 2023. And there was no let-up in October when warming also stayed high at 1.7°C, inching us up to 1.43°C of warming for this year; so very close to the Paris threshold target of 1.5°C. To unpack what these unprecedented temperature spikes means for extreme events, melting ice and sea level rise, we sat down with the WMO Director of Hydrology & Cryosphere – Dr. Stefan Uhlenbrook. Find out what he has to say on how soon we will hit 1.5°C, his biggest worries for water, key advice for policy makers plus more below.

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1) CWR: We aimed to stay within 1.5°C under the Paris Agreement by 2100 but it seems that we will likely reach this earlier. Does the recent temperature spike mean that we will reach 1.5°C sooner than we think? Where are we on warming today?

Dr. Stefan Uhlenbrook (SU): Global temperatures depend mainly on solar activity and greenhouse gas effects but also El Niño and La Niña systems, which usually lasts two to five years. We just came out of a La Niña period last year during which the world is on average cooler than it should be but even then we still had many temperature peaks.

The probability is that in the next five years we will cross the 1.5°C threshold…

…now we must hope to stay below 2°C

Now that we are entering the El Niño period, temperatures will very likely rise even further and the probability is given that in the next five years we will cross the 1.5°C threshold. This could be for one year or two years before temperatures could go back down again as we enter the next La Niña period possibly four or five years from now. While it is hard to predict exact temperatures, we can say that really we are reaching the 1.5°C limit.

With warming today, we are very much on track to pass 1.5°C and now we must hope to stay below 2°C. But this will depend not only on El Niño and La Niña but also how much we are able to reduce greenhouse gas emissions as well as the uptake of carbon through carbon capture and storage. But I think we are on the way to 2°C plus but that’s my view.

2) CWR: Already we are facing a “climate hell” of heatwaves, floods, droughts, wildfires all around the world. Clearly this will get worse with hotter temperatures. As water is how we will mainly feel climate change, can you run us through your biggest worries on this front?

Dr. SU: The hazards you mentioned are all interrelated and temperature dependent. But temperature is only one signal, atmosphere changes in composition and precipitation behaviour also manifest as droughts and floods. If we have droughts, the probability for wildfires are much higher because the earth is dry and the heatwaves are connected to that. My worry is there’s not a single one that will get worse, but all of them in a way we don’t really understand at the moment. So the biggest worry is that these multiple hazards, which are interdependent, will all increase in probability and severity.

The biggest worry is that these multiple hazards (heatwaves, floods, droughts, wildfires), which are interdependent, will all increase in probability & severity

As a hydrologist and water expert I’m a bit biased, but what all our data tells us is that in many parts of the world, we will have more severe and frequent floods as well as droughts; and it is very likely that this will continue further. And that is very damaging for society – it’s the biggest killer and it comes with economic damage. So “climate hell” as you call it will become more frequent and severe especially with floods and droughts – it’s water-related.

The crazy thing is that the average water availability might not even change that dramatically. But it’s the extremes that are changing and that’s what’s introducing larger risks.

3) CWR: Does this mean the “slower moving” water risks – rivers running dry and sea level rise – are now moving faster than we think?

Dr. SU: What the data tells us with droughts or rivers running dry is that it’s become longer and more severe – even lower levels are becoming more frequent. We have also just published our annual “State of Global Water Resources” report, in there you can see areas where river discharge conditions are below or much below normal conditions for 2022. The duration of how low the river is increasing is getting more severe but not really faster, so I think ‘faster’ is not the right term here.

 With droughts or rivers running dry is that it’s become longer & more severe…

…but with SLR, it’s getting faster

But when it comes to sea level rise, you could say that sea levels are rising faster. There is data for a number of decades that show the gradient of sea level rise increased over the last 10-15 years. Sea level rise is now steeper and we see more rapid movement. And with the accelerated melt of snow and ice, it likely that sea level rise may accelerate more in the coming years. There’s also positive feedback from permafrost melt – if it’s getting warmer, there’s more emissions from permafrost which will lead to even more warming. This, unfortunately, positive feedback mechanism could lead to even faster sea level rise. It’s a bit different for sea level rise and droughts but it really doesn’t look good at the moment.

4) CWR: Sea level rise is irreversible even if we stop warming today. Asia is clearly vulnerable as many of our capitals, cities and rural population live along the coast – should we start adapting now? Can we really not rule out more than 2m of SLR by 2100 as warned by the IPCC AR6?

Dr. SU: The prediction for sea level rise is significantly uncertain – between 40cm and 1-2m. You will find different models for 2100 predictions – more than 1.5m are very low likelihood but very severe impact scenarios. So although low likelihood, I would say we cannot rule out 1.5m or 2m of sea level rise completely for the next 100 years.

“…we cannot rule out 1.5m or 2m of sea level rise completely for the next 100 years”…

…a new type of city planning is necessary

The vulnerability of Asia is also very true. Indonesia is moving its capital to a different island now because large parts of Jakarta is now below sea level. But the city is also sinking because of the overuse of groundwater – so there are two mechanisms.

It is irreversible yes, we have to adapt and we have to become more sustainable. Particularly, poorer populations will suffer more. We will have to build houses differently; build more dams, ensure natural water storage capacity and overall physical protection. Integrating a range of different types of adaptation strategies will be needed – a new type of city planning is also necessary.

5) CWR: Are we prepared for these escalating and compounding water risks? What should we focus on first – decarbonization, adaptation or both? Is 1.5°C by 2100 still a possibility?

Dr. SU: As I said, we might cross the 1.5°C threshold in the next five years, at least for one year – there is a significant probability for that. To predict what happens the next 80 years, I think it is unlikely that 1.5°C will still be a possibility unless we are really able to scale up carbon capture and storage. There is increasing research in China and many parts of Europe & Iceland are investing a lot in this. The US also has new programs on technologies but we are not there yet. If we are able to reduce carbon in the atmosphere through green engineering methods from a societal and environmental point of view, we might stay at least below 2°C – if we are very lucky. But I must say, the current predictions are much higher and efforts need to be upscaled further.

It is unlikely that 1.5°C will still be a possibility unless we really scale up carbon capture…

…either way, adaptation & decarbonisation are an absolute must

Adaptation absolutely must happen and decarbonisation as well. We cannot wait for an engineering breakthrough in the future to save us. We must adapt now, city planning can be improved with climate risk assessments and risk management approaches. We must also decarbonise our style of living – this has to do with energy consumption or moving towards renewables; or even our diet – especially if we eat lots of red meat or animal products which has a high carbon footprint. How we produce food is also very important as there are agriculture emissions to consider. We need to decarbonise as much as we can.

6) CWR: If you could give one message/piece of advice to key stakeholders, policy makers and governments what would it be?

Dr. SU: Just returning from the One Planet Polar Summit, I think the need for more research is clear. Many people say it’s only a question of implementing what we know already – yes, we know a lot now, but we need also a lot more research. We need to invest in knowledge generation, knowledge sharing, and knowledge implementation – from research to operations, I think that should get much more priority.

Key pieces of advice:
1) put subsidies to fossil fuels to renewables instead
2) invest in knowledge & research application

Also, we need real long-term commitment. Policymakers, especially politicians in democracies are particularly active in their elective periods. But we need a longer-term vision, strategy, and commitment for the countries; not until the next re-election period. We must change employment to match future sustainable industries and stop subsidies to heavy emitting sectors.

My main advice is: stop the subsidies to fossil fuels which are wrong; we are burning way too much. Instead, we must put these subsidies towards renewables and minimize their environmental footprint including the critical impacts on land and water. So my key pieces of advice are: invest in knowledge & research application and stop fossil fuel subsidies.