Introduction
Have you checked out the RAF site? If so, and you want to know more about global warming, the RAF invites you to take a Deep Dive into the mechanisms fuelling climate change, and their consequences, for both our planet and our economies. The RAF will expand on the subjects discussed in The Issue on the RAF site and cover the following subjects:In Chapters 1 to 12, the RAF presents detailed peer-reviewed, fact-based science proving that global warming is real and accelerating, with devastating consequences.In Chapter 13, the RAF presents compelling economic evidence that rapidly transitioning to renewable energy and phasing out most biofuels, factory farming and factory fishing would not only save the planet for our children and grandchildren but also deliver substantial financial and health benefits. The transition would put substantial money back into our pockets, leaving one critical question unanswered: why aren’t we making the switch immediately?

In Chapter 14, the RAF contends that despite widespread climate change denial and apathy, a Climate Repair Deal is still feasible. However, humanity may run out of time before crossing irreversible and deadly tipping points. This is where Marine Cloud Brightening (MCB), a mild cloud-engineering technique, could offer us just enough time to implement the Climate Repair Deal’s three “Rs”: (i) rapid greenhouse gases (GHGs) Reduction, (ii) substantial GHGs Removal, and (iii) Arctic Refreezing. The RAF concludes with muted optimism: the real question is not whether we can afford the Climate Repair Deal; the real question is whether we can afford not to choose it.

The “napkin diagram”

Inspired by the science communication of Dr. Marshall Shepherd.

The original napkin diagram has been used, adapted and detailed in many publications ever since.The “napkin diagram” above shows how the three Rs of the Climate Repair Deal — Reduce, Remove and Refreeze — interact. Reduce (“cut emissions”), if done aggressively, bends the rising global-temperature curve (red) toward stabilization (purple). Remove (CDR: Carbon Dioxide Removal), if done at very large scale, lowers CO₂ levels back toward pre-industrial levels (light blue).

While these strategies are important, overshooting (the grey zone) in the hope of correcting later carries the existential risk of crossing critical tipping points that could lead to uncontrollable global warming. Once a tipping point has been crossed, a reduction of GHG concentration does not lead to a return to the original climate situation. (In Chapter 9, Tipping Points, the RAF emphasizes that tipping points are the most catastrophic, most existential and most underestimated aspect of global warming.)

Only Solar Radiation Management (SRM) — for example by reflecting sunlight back into space — can promptly mitigate severe climate impacts and, at the same time, prevent the crossing of tipping points. SRM provides valuable time for the other two strategies to be implemented effectively. By cooling down the planet, SRM allows us to Refreeze the Arctic. The RAF advocates MCB (Marine Cloud Brightening) as the timeliest, mildest, cheapest and by far the safest SRM method (see the Geoengineering tab on the RAF site for an in-depth discussion).

Without MCB, we risk crossing tipping points within the next 30–50 years, causing global warming to spiral out of control. No amount of Reduce and Remove will then be able to cool our planet down. Time is running out.

But first, a little history.