solutions: reduction and mitigation

The ultimate solution to climate change is clear: we need to drastically reduce greenhouse gas emissions by replacing fossil fuel consumption with renewable energy.

If all human emissions stopped today, the impact would be slow but steady: temperatures would continue to rise for a few decades as a result of the natural process whereby ocean currents bring excess heat stored in the deep ocean back to the surface.  However, as soon as this excess heat is released to the atmosphere and is radiated out to space, the temperature would stabilize. Without further emissions or anthropogenic influence, natural processes would begin to remove excess carbon dioxide from the atmosphere and temperatures would gradually begin to fall.

Mitigation

Achieving zero emissions by ending the era of fossil fuel clearly continues to be a major challenge for governments. In the meantime, ways to offset emissions either naturally or by looking to geoengineering projects are being explored. Nature-based mitigation includes restoring areas of blue carbon such as mangroves or seagrass beds and protecting marine ecosystems. Increased numbers of larger organisms, such as fish or whales, would transfer organic carbon from surface waters to deeper layers through faeces and deadfall, slowing the return of that carbon to the atmosphere. The ocean itself could play a huge role in offsetting emissions if investment in the protection and preservation of blue carbon ecosystems increases, benefiting the ocean and coastal communities alike while reducing our carbon footprint.

Proponents of geoengineering, a deliberate intervention in the climate system, see alternative ways forward. One branch of geoengineering involves solar radiation management, which aims to block solar radiation and bounce it back to space using reflective particles or aerosols introduced into the atmosphere. By reflecting sunlight, the planet would cool and global warming would be reversed. The other branch, using ocean-based negative emission technologies, has set its sights on the ocean, using a variety of methods to directly remove or store CO2 or to increase phytoplankton growth.

OceanNETs, an EU-funded project involving many European research and academic institutions, hosted at the GEOMAR Helmholtz Centre for Ocean Research Kiel, aims to determine to what extent, and under which conditions, the large-scale deployment of ocean-based negative emission technologies could mobilize the ocean in order to contribute to climate neutrality and the goals established in the Paris Agreement. 

Geoengineering projects outlined on the OceanNETs website include:

While some see geoengineering as a promising avenue of mitigation, many are calling for a precautionary approach and the impact of such projects is under review, including by the Conference of Parties to the Convention on Biological Diversity. Technical and regulatory matters on geoengineering in relation to the CBD were included in a study on the Impacts of Climate related Geoengineering on Biological Diversity (updated October 2016) and the CBD’s de facto moratorium on climate-related geoengineering was reaffirmed at the 2024 COP16 in Cali in its outcome document (see paragraph 6 of Decision CBD/ COP/16/L.24. Marine geoengineering is limited to strictly-controlled research by regulations established under the IMO Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972 (London Convention) and its 1996 Protocol (London Protocol) (often referred to as the LC/LP) which provide detailed guidance regarding ocean fertilization and carbon storage. A review of ocean fertilization under these instruments can be found here.

Calls for a moratorium on geoengineering, similar to those on deep seabed mining, are getting louder, following which geoengineering activities should only be viewed as a viable solution when we know the true effects of the activities. The report Fuel to the Fire: How Geoengineering Threatens to Entrench Fossil Fuels and Accelerate the Climate Crisis of the Centre for International Environmental Law investigates the role of the fossil fuel industry in developing, patenting, and promoting key geoengineering technologies and recommends that:

“Humanity has a limited and rapidly closing window to avoid truly catastrophic climate change. To keep warming below 1.5 degrees, the world must reduce greenhouse gas emissions 45% by 2030 and reach net zero emissions by around 2050. By entrenching fossil fuel interests and promoting continued reliance on fossil infrastructure, geoengineering distracts from more viable solutions and threatens to exacerbate the climate crisis, while exposing large parts of the world to new and significant risks. The managed decline of fossil fuels is both a necessary and achievable solution to the climate crisis.”