Geoengineering is the in-case-of-emergency-break-glass response to climate change. It means taking action to alter the atmosphere to reflect the sun’s radiation and temporarily slow global warming.
The controversial idea has largely been seen as a last resort given concerns that a geoengineering intervention could go wrong and have unintended negative impacts.
Now nearly 100 climate experts internationally have signed an open letter urging the world to accelerate and beef-up geoengineering research — but not deploy the technology.
They don’t mince words.
“Even with aggressive action to reduce [greenhouse gas] emissions it is increasingly unlikely that climate warming will remain below 1.5-2°C in the near term,” the scientists said in a letter posted Monday.
The planet has already warmed 1.1 degrees Celsius, and the Paris climate agreement aims for 1.5 degrees. Last year, the world set a new record for carbon dioxide emissions, the IEA announced Thursday.
The leading strategy for slowing warming is “solar radiation modification (SRM),” where particulates or aerosols are added to clouds or the stratosphere. Aerosols can reflect sunlight or reduce the amount of heat trapped in the atmosphere, depending on the approach.
The researchers note there will be increasing pressure to use geoengineering as the impacts of climate change become more disruptive. But there’s “significant uncertainty” about the impacts of SRM.
“While we fully support research into SRM approaches, this does not mean we support the use of SRM,” the scientists said.
University of Washington associate professor Sarah Doherty led the effort to issue the letter. The 98 signatories include climate luminary James Hansen, as well as Doherty and 10 additional researchers from the UW’s Department of Atmospheric Sciences and its Cooperative Institute for Climate, Ocean and Ecosystem Studies.
The letter coincided with a publication from an expert panel convened by the United Nations’ Environment Programme to examine SRM. It came to similar conclusions.
“[T]he international community must invest in understanding the potential risks and uncertainties of SRM technologies. We only have one atmosphere. We cannot risk further damaging it through a poorly understood shortcut to fixing the damage we already caused,” states the forward to the report.
The worries about the need for more research appear well-founded.
A tiny startup called Make Sunsets claims to have launched balloons carrying sulfur particles in an effort to commercialize geoengineering, as first reported in December by MIT Technology Review. The company’s actions are raising serious concerns that this is just the start of rogue SRM efforts.
GeekWire caught up with Doherty to learn more about the issue. Questions and answers were edited for clarity and length.
GeekWire: What was your role in putting together the letter?
Doherty: While I organized the letter, it is the result of many weeks of collaboration and input from the signatories.
Why is this letter important, and important right now?
The letter was motivated by scientists’ awareness of the reality that greenhouse gas emissions reductions alone likely will not allow us to avoid catastrophic climate impacts, and the suffering and damage to natural systems that will accompany these impacts. This reality has rightfully come with an increase in public discussion of climate intervention, not all of it very accurate or representative of how the scientific community is approaching this problem.
We think it’s important that the public understand what is motivating scientists to support research on this topic, how it fits in with climate research more broadly, and to make the important distinction between supporting objective research to rigorously evaluate climate interventions versus supporting actively using them.
How quickly could the scientific community scale up research like yours and others to address fundamental questions about SRM and other climate uncertainties?
A recent report put out by the organization SilverLining does a nice job of addressing the scope of research needed to address key questions about the potential efficacy and impacts of SRM on climate risk. As highlighted in that report, most of the needed research is fundamentally climate research, and would simultaneously help reduce existing important uncertainties in how human activities are already affecting climate.
In an ideal world, how would SRM be implemented?
Today, we lack the scientific information required to know whether SRM can be safely and effectively implemented, and if so, what would be best. These are critical questions, which is why research is so important.
How likely do you think it is that SRM will be required to manage the impacts of climate change and avoid tipping points that trigger runaway warming?
Unfortunately, the uncertainties we have in projecting abrupt changes in natural systems and gaps in knowledge about climate interventions make it hard to answer this question. Given the significant risks of crossing tipping point thresholds in the next few decades, it is a very important area of focus and increased investment for scientific research.
