What Are Negative Emissions?

After the Paris Climate Summit in December 2015, 195 nations from around the world agreed to curb global warming to below a maximum 2°C and to preferably under 1.5°C. Each country has compiled a list of its own promises and targets in a bid to meet this shared goal, including phasing out polluting forms of energy generation and investing in renewable technology.

However, scientists now claim that simply transitioning away from fossil fuels towards greener energy sources will not be enough to keep global temperatures from rising by 1.5°C or less, and may not even be sufficient to stay under the 2°C threshold. Instead, they insist that technologies which result in “negative emissions” must be in place by the 2030s if these goals are to be met.

An imperative objective

When the nations of the world met in Paris two years ago, it was unanimously agreed that preventing global temperatures from increasing by 2°C from pre-industrial levels was vital to safeguarding lower-lying countries and islands, preventing extreme weather phenomenon from occurring regularly and safeguarding food production resources.

Since the signing of the Paris agreement, there has been movement from governments all over the world. Even among developing nations, a growing market for continuous emissions monitoring systems (CEMS) shows that public awareness of the problem is at an all-time high, and governments are making strides to meet the challenge.

But while each country has devised its own set of measures designed to fulfil its obligations, it may not be enough, according to some scientists. Simply reducing the amount of carbon we expel into the air might not go far enough; instead we must also bring about negative emissions by sucking some of the existing greenhouse gases (GHGs) that have already been emitted from our atmosphere.

“It’s something you don’t want to talk about very much but it’s an unaccountable truth: we will need geoengineering by the mid-2030s to have a chance at the [1.5°C] goal,” explained Bill Hare, chief executive of Berlin-based science and policy institute Climate Analytics.

What are negative emissions and how can we achieve them?

 Simply put, negative emissions mean reducing the amount of carbon by capturing it, extracting it from the environment and storing it in a safe place. This is commonly known as carbon capture and storage (CCS) and scientists have been investigating the process for many years.

One such technology involves a gas analyser fitted at the point of emissions, which not only provides effective monitoring of the carbon being released into the air, but could hopefully one day extract some of that pollutant before it is expelled.

Another idea is to plant vast swathes of forested area with the explicit purpose of removing carbon in their vicinity (since plants absorb CO²), then use the wood as fuel for electricity afterwards. The main obstacle comes when deciding what to do with the emissions produced from that process, and indeed, what to do with the carbon in any of these scenarios after it has been captured.

Perhaps the most popular suggestion involves pumping the carbon underground, a proposal supported by the United States and other countries intent on pursuing coal as a long-term energy source. However, such a plan has not been sufficiently developed to be implemented on a large scale, and could also take up valuable land needed for food production. It also brings into question the issue of land ownership, which could prove problematic, as well.