The problem isn’t the carbon in the air, it’s the carbon in the ground.
All approaches to climate change must address this new reality: with the methods we now have for extracting fossil fuels, we have enough rope to hang ourselves. The hope of the early environmentalists, that the world would run out of hydrocarbons before we did irreparable damage, is no longer realistic. Now, we must confront the facts – preventing climate change requires either leaving fossil fuels in the ground, or burning them without releasing their carbon into the atmosphere.
Renewables and nuclear power present the possibility of doing the former. If we supply our energy requirements without using fossil fuels, we can also leave our unburned hydrocarbons in their wells. This has the added benefit of saving the land around them, which can be damaged by some methods of extraction, although many renewables are not without their own damage and the downsides of nuclear are well known.
The problem is, our energy requirements are not fixed. Over history, as our supply expands, our demand grows with it. Electricity has gone from powering lights to heating whole homes, and may well end up powering our transport network as well. The worry is that even if we manage to build enough clean sources of energy to replace our usage of fossil fuels, they will end up merely augmenting that usage.
This is where the other method of tackling climate change comes in. With innovative technologies such as carbon capture and storage (CCS), we need not worry about future generations, or about our own extraction of fossil fuels to feed the rising demand for energy. Instead, we can spend the time and money required to make our fossil fuels clean, and then allow our energy policy to focus on the mix of sources which most efficiently satisfies demand.
Eventually, we will have to decarbonise our economy. Though there may be more fossil fuels under the ground than we once thought, they still aren’t unlimited. Yet that concern is secondary to stopping climate change.