A natural solution to address multiple risk dimensions:
Forests were fundamental to the creation of the biosphere as we know it. Helping them recover at a grand scale is fundamental to keeping nature safe. Conversely, if forests go, so do we.
Photosynthesis produced virtually all the oxygen in the atmosphere (initially via bacteria, then via plants). It is such an efficient process that a single planted tree (cost ~$2) can draw down between 1-2 tons of CO2 during its growth phase. So as a proven carbon-sequestration system, no other ‘technology’ today comes close.
Yet, planting millions of trees alone won’t do the job: we need to restore biodiverse natural forests and peatlands that host diverse and cooperating communities of plants and animals. By doing so, we not only create an optimal and durable carbon sink for excess atmospheric carbon, we also gain the other essential benefits: stability of soil, water and weather systems, and diversity of animal life.
Equally, we need to ‘throw the kitchen sink’ at the de-carbonisation challenge. So, while nature-based solutions have tremendous advantages, any approach (e.g. Direct Air Capture, olivine sand, etc) that has a chance of removing CO2 from the atmosphere permanently (net of energy and risks required to operate) should be embraced in parallel. And of course, our governments must find ways to slow and eventually stop entirely the destruction of precious old-growth forests in areas such as the Amazon, Borneo and Central Africa.