Ocean-Based Cooling Strategies

The Blue Cooling Initiative (BCI) is an urgent and critical response to the accelerating climate crisis, spearheaded by a diverse coalition of scientists, opinion leaders, civil servants, and politicians. The Initiative focuses on advancing ocean-based cooling strategies, with a particular emphasis on Marine Cloud Brightening (MCB). By enhancing cloud reflectivity, MCB aims to increase the amount of sunlight reflected back into space, thereby cooling the planet.

Addressing Climate Catastrophe: A Unified Approach

Pollution, in all its forms, is destroying our ecosystems and the habitat essential for human life. Among the most critical pollutants is excess man-made atmospheric CO2, a major driver of global warming. To safeguard our future, we must restore CO2 levels to those conducive to a stable human climate. However, this restoration will take considerable time. Meanwhile, we face the immediate threat of global warming, which demands urgent action.

The Stockholm Resilience Centre highlights two main boundaries critical to our planet’s survival:

  • Climate Change: To stabilize our climate, we need to reduce CO2 levels to 280 ppm, which means sequestering 1.1 trillion tons of CO2 as quickly as possible. This requires us to cut emissions drastically so that sequestration exceeds emissions, making current “net zero” targets inadequate.
  • Biodiversity: Protecting 50% of all land and sea areas is essential. Reducing biodiversity loss inherently benefits all planetary boundaries, making nature the true indicator of progress.

The Blue Cooling Initiative highlights a third main boundary critical to our planet’s survival:

  • Global Temperature Rise: We need to cool global temperatures back down by 1°C or more, focusing on ocean-based cooling technologies like Marine Cloud Brightening.
Tipping risk of the Atlantic Ocean’s overturning circulation, AMOC. Keynote by Prof. Rahmstorf

One of the most ominous risks for Europe is that of a major change in Atlantic ocean currents. Recent science suggests it has been greatly underestimated in the past. Prof. Rahmstorf (Earth System Analysis – Potsdam Institute) presents his keynote on the AMOC (May 2024).

Since the Earth Summit 30 years ago in Rio, the global community has focused primarily on reducing CO2 emissions to address the climate crisis. Despite significant financial investments, global emissions are not decreasing quickly enough to avert severe consequences. Global warming has already surpassed preindustrial levels by over 1.5°C, resulting in more frequent and severe extreme weather events and destabilizing ice sheets. This situation heightens the risk of substantial sea level rise and other catastrophic impacts.

Scientific consensus now indicates that critical climate tipping points—affecting the Antarctic and Greenland ice sheets, Northern permafrost, coral reefs, and the Atlantic circulation system—can be triggered at temperature increases as low as 1°C to 2°C. Previously, it was believed these tipping points would only be activated at much higher temperature increases over longer periods. Given these developments, it is clear there is no safe margin left to ensure the future of humanity and the natural world.

Advocating Climate Action And Climate Justice

Reducing emissions is too small, slow, controversial, difficult and expensive to make any difference to temperature in the short term. And unless we can control temperature rise in the short term, all other political goals are impossible. The systemic disruption caused by higher temperatures, if allowed to occur, will undermine all discussions on critical issues such as climate justice, ecology, well-being and stability.

The current albedo collapse is almost 1% per decade. The planetary reflectance is now measured by NASA at 98 watts per square meter compared to 100 w/m2 in 2001. The dimming of the world since 2015 has the warming effect of 100 ppm of CO2 emissions, according to James Hansen, Professor Climate Science, Awareness and Solutions Program Earth Institute at Columbia University.

  • The idea of mitigation deterrence is incoherent and ideological. Reducing emissions cannot mitigate climate change in a relevant time frame, while higher albedo can. So it doesn’t make sense to say that increasing albedo could deter mitigation.
  • We have not yet seen the full warming impact of current CO2, due to the delay caused by the mixing of the oceans. This has slowed the heat for a while.
  • Reducing emissions can have virtually no effect on warming.

Human Cost and Global Disparities

What’s often missing from the conversation is the human cost of climate change. Health impacts, such as increased respiratory and cardiovascular diseases, and food security threats due to disrupted agricultural systems, are already disproportionately burdening the Global South. Additionally, the economic costs of inaction are staggering. Property and infrastructure damage from extreme weather events are becoming more frequent and severe, and we are running out of building materials to replace what is, and what will be, lost.

Emission reductions alone cannot reverse the current trajectory or restore global climatic conditions to those of the 20th century. While emission reductions and increased atmospheric CO2 removal are essential, they cannot immediately reduce the already unsafe temperatures and impacts, even if implemented rapidly. Moreover, even with the ambitious goal of eliminating emissions by mid-century, global average temperatures are projected to be 2°C to 3°C higher than preindustrial levels, leading to a dystopian future.

Triple Climate Conundrum

We advocate the world community urgently come together to carry out an equitable, science-based plan of action that includes the Triple Climate Conundrum:

  1. Direct Climate Cooling: Through sunshine reflection, ecosystem restoration, and other safe and effective means within this decade.
  2. Accelerating Emission Reductions: Particularly targeting methane due to its short atmospheric lifetime and prevention of sea-level rise.
  3. Enhancing Carbon Removal and Sequestration: deploying large scale removal of atmosphere carbon dioxide and other greenhouse gasses.

The goal of these actions, along with enhanced and transformative adaptation and regeneration measures, is to reduce the average global temperature increase to well below 1°C in the coming decades. Doing so will sharply reduce weather extremes, slow or stop the collapse of key ecosystems, and help ensure a liveable planet for humanity and the natural world.

Among these, Direct Climate Cooling (DCC) is the most urgent to prevent further temperature increases and provide time for emission reductions and carbon removal to accelerate. Promising DCC approaches can likely reduce global average temperatures within years rather than decades, at a cost in the billions rather than trillions, and with acceptable safety levels compared to continuing without DCC.

Marine Cloud Brightening

One of the most effective temporary planet cooling measures is Marine Cloud Brightening (MCB). This technology increases the albedo of clouds over the ocean, reflecting more sunlight back into space and cooling the planet. MCB involves spraying seawater to create tiny salt aerosols that enhance the reflectivity of clouds. Research from the University of Edinburgh, Cambridge University’s Climate Repair Centre and other institutions such as the TU Delft supports its potential effectiveness.

If we fail to implement necessary measures within the next 5 to 10 years, global temperatures could exceed critical thresholds, leading to severe climate disruptions like heatwaves, droughts, typhoons, and floods. As Swedish professor Johann Rockström of Stockholm University warns:

“Push these tipping points too far and they will shift from supporting humanity to undermining it.”

Swedish professor Johann Rockström (Stockholm Resilience Center)

We are a growing coalition of scientists, opinion leaders, civil servants, and politicians advocating for urgent action. It is time to organize societal acceptance, secure funding for R&D, and remove barriers through coalition-building. By deploying the Climate Triad, we can reduce temperatures, protect ecosystems, and offer hope for a better future.

As Sir David King, founder of the Centre for Climate Repair at Cambridge University, stated:

“What we do over the next three to four years, I believe, is going to determine the future of humanity. We are in a very desperate situation.”

Sir David King (Founder & Former Chair at Centre for Climate Repair)

By embracing an equitable, inclusive and scientifically grounded approach, the world community can strive towards a safe and healthy climate, minimizing polarization and fostering global cooperation in the fight against climate change.