The Paris Agreement focuses on keeping the global temperature rise in this century to well below two degrees Celsius above pre-industrial levels – ideally to 1.5 degrees Celsius – to avoid “severe, widespread and irreversible” climate change effects. On current trends, the world is likely to pass the 1.5 degrees Celsius mark before 2050, unless the net zero emissions target is reached.
Ending fossil fuel combustion
Ending the burning of coal, oil and natural gas will be the best way to solve climate change. Yet oil is at the core of the global economy in terms and reducing dependence on fossil fuels by carbon-neutral biofuels will see food prices rise and forests destroyed to make way for the planting of these new fuels. Although nuclear power does not emit greenhouse gases, it does produce radioactive waste which causes its own problems.
Cutting energy demand
Stop wasting energy. Turn lights off when you leave the room and drive a fuel-efficient vehicle. Be mindful of water usage and think green about everything from lighting, heat, new appliances and insulation.
Insulating buildings, which contribute about 30 per cent of all greenhouse gas emissions, saves money over time after the initial investment. Good roads allow cars to run more efficiently, cuts greenhouse gas emissions and supports economic growth.
Work from home or move closer to work. Use trains and buses or any form of transport that requires only human energy. Air travel is one of the fastest growing sources of greenhouse gas emissions, which occur higher in the atmosphere. Trains can replace planes for shorter trips.
Buying less means that fewer fossil fuels will be burned to extract, produce and ship products around the globe. Buy used and buy green. This could mean a second-hand hybrid car or a basket of food without packaging.
Following a vegetarian diet can support the fight against climate change, but it is not a simple equation as the value can be diminished by the use of fertilisers and the fuel needed to harvest and transport goods to your local store. Even organic food can be flown half-way around the world. Scientists have estimated vegetarians save 1.5 tons of greenhouse gases through their food choice than do their carnivore peers. In addition, far more land is needed for livestock farming, so a shift to a vegetarian diet would free up more room to plant trees.
Save the forests
Acres of trees are felled each year, which sends 1.5 billion metric tons of carbon to the atmosphere. Improved forest management, together with paper recycling, could cut this figure significantly. Billions of trees will have to be planted, and people may have to make choices between using the land for food or using it for energy crops.
With 6.6 billion people living on the planet and nine billion predicted by the United Nations by 2050, life on Earth is not sustainable for a growing population. Falling birth rates have begun to reduce or reverse the population explosion.
There are currently not enough biofuels to replace fossil fuels, and whether they be ethanol derived from crops or hydrogen electrolysed out of the water, all have some drawbacks such as driving up food prices. Low-emission energy generation, whether solar-thermal or nuclear power are required to radically reduce greenhouse gas emissions, along with other sources still being studied, including solar energy stations in orbit or even fusion.
To date, the full implications of geoengineering actions are unknown, though the technology to curb climate change already exists, even machines that will have to suck carbon out of the air and store it underground. Each will have consequences that could make the solution worse than the original problem. Yet carbon capture and storage could be critical to any serious effort to combat climate change.
If nothing is done to reduce climate change now, removing CO2 from the air, and sequestering it underground, in the deep ocean, or trees or the soil for storage over many centuries will become more likely. However, this is a challenge in terms of logistics and economics as much as being a technical challenge.
Reduce Earth’s net absorption of sunlight
Intervening to block sunlight or reduce greenhouse gases, is a potential last resort for addressing the challenge of climate change. This could be the release of sulphate particles in the air to mimic the cooling effects of a massive volcanic eruption; placing millions of small mirrors or lenses in space to deflect sunlight. Creating a stratospheric aerosol layer or placing shields in space could offset the surface warming caused by increasing greenhouse gases but would not stop ocean acidification. It would also need to be well maintained.
With the best will in the world, additional global warming is inevitable and will require some adaptation. Adaptation is actually needed now in response to climate change that has already occurred. There are limits to adaptations that are possible, particularly in less developed regions, so the sooner the actions are taken to adapt, the better.
The risks and opportunities associated with climate change need objective scientific information on the consequences of alternative pathways, which take into consideration the ethics and value judgements about the wellbeing of people, economies and the environment. The solution to climate change needs the actions to happen together to achieve the Paris Agreement of 1.5C.