IPCC cautions on relying on BECCS, NBS, hydropower for net-zero

Nations and companies pursuing net-zero goals must be careful when they turn to "holy grail" decarbonizing tools like hydropower, nature-based solutions (NBS), and bioenergy with carbon capture and storage (BECCS).

The warning came in the Intergovernmental Panel on Climate Change's (IPCC) Sixth Assessment Report released on 28 February, as it presented a picture of "potentially irreversible" climate change impacts.

Both the US and the EU, which have pledged to reach net-zero by 2050, acknowledged the urgency of the situation presented in the IPCC report. "The IPCC report underscores the ways climate impacts are affecting lives and livelihoods globally now," said US Secretary of State Antony Blinken in a statement.

The Sixth Assessment came from Working Group II, and it's the second of three reports to come after COP26 in November. Its key finding is that there are limits to how well humans can adapt to damage done by a hotter and wetter climate.

Evidence of limits on what can be saved is strongest for small island states but also cities, food, and water systems in South America, as well as coasts in North America and Africa, a chart within the IPCC report shows.

Even so, adaptation is needed now, and steps must be taken soon. "The evidence shows that taking action now to ensure all [net-zero] infrastructure is designed to be resilient to future climate from the outset is more cost-effective and efficient than retrofitting it later," Richard Dawson, a Newcastle University professor and member of the working group authoring the report, told Net-Zero Business Daily by S&P Global Commodity Insights.

Not only existing infrastructure, but also net-zero infrastructure requires adaptation. "If we manage to limit global warming to 1.5 or 2 degrees Celsius, there will still be increased risk to society and infrastructure installed to achieve net-zero," added Dawson.

Mitigation finance so far has dwarfed adaptation finance, for example in national net-zero plans, partly because mitigation is cheaper than adaptation.

Renewable energy adaptation

Using renewable energy — specifically generation such as wind, solar, and small-scale hydropower — can reduce cities' vulnerabilities to climate change by adding diverse and decentralized power sources, the report found.

But at about 2 degrees Celsius global warming, snowmelt availability decline and global glacier loss would diminish water availability for hydropower. "Adaptations for hydropower and thermo-electric power generation are effective in most regions up to 1.5 degrees to 2 degrees Celsius, with decreasing effectiveness at higher levels of warming," the report warned.

More energy sources should be combined with measures that add flexibility. For example, energy storage, energy efficiency, and smart-grid technologies. Countries also need "robust" networks and systems to enable rapid response to outages.

Governments must restructure energy markets and update equipment design standards to encourage adapting power plants to climate change, the report added.

Global Wind Energy Council CEO Ben Backwell warned that because the report is only published every 6-7 years, this would be the "last call to action to all policymakers to strengthen climate ambitions" and that "near-term actions to cut emissions," for example deploying renewable energy, were the only real solutions.

A digitized power sector should work with the sectors that rely on it to prevent blackouts from leading to humanitarian catastrophe. "Cascading failures have been observed around the world as loss of power or [internet] can lead to knock-on disruption to other key services such as lighting, heat, water, and sanitation," Dawson said.

BECCs, bioenergy, NBS risk being "maladaptive"

The report warned that net-zero infrastructure that is either wrongly implemented or inflexible could be costly to correct and could do harm.

One technology seen as crucial for helping to attain needed global emissions cuts is BECCs, or the burning of carbon-absorbing biomass while capturing its emissions to attain negative emissions overall.

The report's authors noted that BECCS would be necessary to attain Paris Agreement goals, but has to be built carefully to avoid taking up cropland needed to grow food and habitats for animal species.

"BECCS is an integral part of all widely accepted pathways to holding global temperature rise to 1.5°C. This requires large areas of land which can conflict with the need to produce food and 30 protect biodiversity," the report stated.

Supporting the need for care with BECCS, a report released this month by the European Academies' Science Advisory Council said "the science does not support launching into the conversion of existing large-scale forest biomass power stations to BECCS," but instead supports power plants using local feedstocks such as grass or waste.

The panel's warnings extended to NBS, for example, tree planting used by many energy companies trying to reach net-zero targets.

The IPCC supported reforestation of formerly forested areas, such as in urban areas, but it warned planting trees can also lead to climate change because draining land for afforestation can cause an overall increase in GHGs and warmth.

It recommended not planting trees in open grasslands, densely wooded savannas, peatland, and shrubland, but instead restoring existing forests and ecosystems.

Nevertheless, nature-based coastal adaptations are seen in a more positive light.

Experts agreed on the need to shift adaptation finance away from building structures like seawalls towards cheaper NBS like beach and shore nourishment, although they noted that the idea NBS alone could provide a solution to climate change was a "misunderstanding."

While effective in the short term, many adaptation solutions can increase exposure to climate risks unless they are integrated into a long-term adaptive plan, the report found. For this reason, city development plans should be taking adaptation into account today.

The report references a Spanish government irrigation project intended to adapt farms to climate change that inadvertently made small-scale producers more vulnerable to climate change because they sold their land to the project.

Other adaptation options include managed migration, but the report noted "important uncertainties [remain] as international regimes develop around human rights, migration, displacement and the implications for the national sovereignty of disappearing land spaces caused by climate change."

This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.