Creating a forest in the desert by pumping gallons of desalinated water a possible solution to climate change.
Picture this: desalinization plants turning salty ocean water to useable fresh water. Channel this water in pipes over hundreds of miles where fledgling and thirsty young eucalyptus trees grow in the desert, in fact, the biggest deserts on the planet: the Sahara and the Australian Outback. Global warming solved? Scientists Leonard Ornstein, Igor Aleinov, and David Rind think so in their paper titled: Irrigated afforestation of the Sahara and Australian Outback to end global warming. Is their solution worth consideration?
David Adam of the Guardian reports that the plan could cost $1.9T, more than twice the amount of schemes for Carbon Capture Sequestration (CCS) technology. Ornstein defends his idea: "When that's compared to figures like estimates of $800B per year for CCS, our plan looks like a loser. But CCS can address only about 20% of the problem at the $800B price. Mine addresses the whole thing. And CCS would involve a network of dangerous high-pressure pipelines coursing through the most developed neighbourhoods of our civilisations, compared to relatively benign water aqueducts in what are presently virtually uninhabited deserts."
However, this solution has major environmental problems that need further investigation. There is a concern among scientists that light energy from the sun will be absorbed in a dark green forest as opposed to being reflected back into space by the currently present white desert sand; there's a possibility that these forests would heat the planet. Environmentalists are also concerned that the deserts' ecosystem would be destroyed. Impacts on the environments caused by construction were not assessed in the study, which is a concern over the amount of carbon emissions caused by concrete production, transportation of materials, and fuel use. The desalinization plants and the water pumps would require enormous energy sources and assuming that this energy should be renewable (solar, wind, tidal,) the plan may be less feasible than just installing a large solar array in the desert. A life cycle assessment of Ornstein's afforestation plan not presented in the current paper is required to be convincing.
Despite costs and environment considerations, the overall problem with this scheme is that it has an all or nothing quality. If we go the afforestation route, CCS should be scrapped entirely based off costs. CCS and similar plans offer time to learn, room to adjust, and room to take detours regarding policy and implementation. Without this flexibility policy makers and world leaders may find the task of a global climate change pact more arduous than it is currently (which remains a nightmare). The authors admit themselves that the need for a climate change agreement is the "most difficult hurdle" in their plan's implementation: "International mechanisms for monitoring and managing (without mangling or strangling) such projects will be essential." The authors recommend, "We must bite the bullet. Global warming will not go away by itself."