Scientists Made a Detailed “Roadmap” for Meeting the Paris Climate Goals. It’s Eye-Opening.

by Brad Plumer (Vox) ... They start with the big picture: To hit the Paris climate goals without geoengineering, the world has to do three broad (and incredibly ambitious) things:

1) Global CO2 emissions from energy and industry have to fall in half each decade. That is, in the 2020s, the world cuts emissions in half. Then we do it again in the 2030s. Then we do it again in the 2040s. It’s simple but staggering. They dub this the “carbon law.” Lead author Johan Rockström told me they were thinking of an analogy to Moore’s law for transistors, and we’ll see why.

2) Net emissions from land use — i.e., from agriculture and deforestation — have to fall steadily to zero by 2050. This would need to happen even as the world population grows and we’re feeding ever more people.

3) Technologies to suck carbon dioxide out of the atmosphere have to start scaling up massively, until we’re artificially pulling 5 gigatons of CO2 per year out of the atmosphere by 2050 — nearly double what all the world’s trees and soils already do.

2017-2020: All countries would prepare for the herculean task ahead by laying vital policy groundwork. Like: scrapping the $500 billion per year in global fossil fuel subsidies. Zeroing out investments in any new coal plants, even in countries like India and Indonesia. All major nations commit to going carbon-neutral by 2050 and put in place policies — like carbon pricing or clean electricity standards — that point down that path. “By 2020,” the paper adds, “all cities and major corporations in the industrialized world should have decarbonization strategies in place.”

2020-2030: Now the hard stuff begins! In this decade, carbon pricing would expand to cover most aspects of the global economy, averaging around $50 per ton (far higher than seen almost anywhere today) and rising. Aggressive energy efficiency programs ramp up. Coal power is phased out in rich countries by the end of the decade and is declining sharply elsewhere. Leading cities like Copenhagen are going totally fossil fuel free. Wealthy countries no longer sell new combustion engine cars by 2030, and transportation gets widely electrified, with many short-haul flights replaced by rail.

In addition, spending on clean energy research increases by “an order of magnitude” this decade, with a sustained focus on developing new batteries, drastically reducing the cost of carbon capture and storage (CCS), and perfecting low-carbon processes for producing steel and concrete, plus improving smart grids, greener aircraft systems, and sustainable urbanization techniques.

Meanwhile, efforts to start pulling carbon dioxide out of the air start this decade. That means reforesting degraded land and deploying technologies such as direct-air capture or bioenergy with CCS to pull CO2 out of the atmosphere. By 2030, we’d need to be removing 100 to 500 megatons of CO2 each year and have a sense of how to scale up.

2030-2040: By this decade, hopefully, we’re reaping the fruits of major technological advances in clean energy. Leading countries like Denmark and Sweden should now have completely carbon-free grids and have electrified virtually all of their transport, heating, and industry. Cars with internal combustion engines “will have become rare on roads worldwide.” (Let that sink in.) Aircraft will be almost entirely powered by carbon-neutral fuels, say, biofuels or hydrogen. New building construction will be largely carbon-neutral, by using emissions-free methods for steel and concrete or through other techniques. And “radical new energy generation solutions will enter the market.” READ MORE Abstract (Science Magazine)