A number of countries have made commitments to move to a net zero emissions economy. This is in response to climate science showing that in order to halt climate change, carbon emissions have to stop – reducing them is not sufficient. ‘Net zero’ means that any emissions are balanced by absorbing an equivalent amount from the atmosphere.
In order to meet the 1.5°C global warming target in the Paris Agreement, global carbon emissions should reach net zero around mid-century. For developed nations such as the UK, the date may need to be earlier. Many have already set such dates.
The science of ‘carbon budgets’
Climate science is clear that to a close approximation, the eventual extent of global warming is proportional to the total amount of carbon dioxide that human activities add to the atmosphere.
So, in order to stabilise climate change, CO2 emissions need to fall to zero. The longer it takes to do so, the more the climate will change. Emissions of other greenhouse gases also need to be constrained. In the Paris Agreement, governments agreed to keep global warming ‘well below’ 2 degrees Celsius, and to ‘make efforts’ to keep it below 1.5ºC.
The Intergovernmental Panel on Climate Change (IPCC) released a report in October 2018 on the 1.5ºC target; it concluded that global emissions need to reach net zero around mid-century to give a reasonable chance of limiting warming to 1.5ºC.
India should announce a target of achieving net zero by 2060. It is vital to appreciate that committing to climate goals is not quite donning a hair shirt: transitioning to that goal through a low-carbon economy offers immense opportunities for innovation, investment and growth.
Transition to a net-zero economy
Use less energy, increase energy efficiency: In order to use less energy, the world needs to deploy more efficient equipment, transport modes and production processes as well as use less primary material. Consumption and production patterns need to change so that we consume less and create products that last. We must move to a circular economy ensuring that every broken, discarded or depleted product can be recycled or reused.
Expansion of renewables provision:Ten years ago, the ability of renewable energy to compete with fossil fuels was viewed with some scepticism. Since then, the use of renewables more than tripled in China and has doubled in the United States. The cost of renewables has been falling steadily, and in 2020 nearly 90% of the increase in total power capacity worldwide came from renewable sources. The more we scale up, the more we reduce our dependence on polluting fuels.
Stop deforestation and use agro technologies
Land use, including forestry and agriculture, accounts for around 20% of global emissions. We need to stop clearing forests to create agricultural land. By using techniques like agroforestry, we can encourage biodiversity while enabling forests to do their job: acting as a shelter for livestock, improving soil quality, managing microclimates and sequestering carbon.
Scale up carbon removal solutions
We already have the natural resources to help absorb CO2 − whether through reforestation or the preservation of areas such as peat bogs which soak up and store carbon. Mangrove forests fulfill the same role with the additional benefit of reducing physical risks such as storm surge and flooding.