From Promises to Actions

Imagine it's the year 2070, and this video has found its way to an Internet archive. Researchers of the future, if you're curious about how we tackled climate change in the 2020s, the answer lies in our commitment to achieving net zero. Over the past few years, more than 70 countries, one after another, have made pledges to reach net zero emissions. This includes nations that have contributed minimally to climate warming, as well as those most responsible for emissions thus far. The message is clear: humanity must strive for carbon neutrality within the next 3 to 5 decades.

However, achieving this goal becomes increasingly challenging the longer we wait. Governments are now factoring in the concept of "negative emissions" to make it viable. This notion forms the "net" part of the net zero promise, suggesting that we can still emit greenhouse gases while simultaneously removing CO2 from the atmosphere.

This concept, known as carbon dioxide removal (CDR), has gained attention and sparked debates. To help us understand, let's consider the bathtub metaphor. Picture the atmosphere as a bathtub and the water within it as CO2. Before the Industrial Revolution, the land and oceans released as much CO2 as they absorbed, maintaining a delicate balance. However, the extraction of coal and oil for industrial purposes disrupted this equilibrium, leading to a surplus of CO2 in the air that natural processes couldn't keep up with.

Approximately 45% of these emissions remain in the atmosphere, contributing to escalating climate disasters. In 2015, representatives from countries worldwide gathered in Paris with a critical goal: to limit global warming to well below two degrees Celsius above pre-industrial levels, aiming for 1.5 degrees. The exact numbers matter less than the fact that each increment of warming increases the risks we face. To address the root of the problem, we must turn off the tap and cease emitting CO2 altogether.

Regrettably, global emissions continue to rise, particularly in Asia, where a significant portion of the global population is emerging from poverty. We now find ourselves nearing 1.2 degrees of warming, and it is clear that we haven't done enough to meet the 1.5-degree goal. Nonetheless, there is hope that realizing the net zero promises as genuine policies could help limit warming to under two degrees.

Here's where it becomes complex. Completely eliminating emissions presents challenges, both in terms of cost and fairness. Hence, many hope to expand the metaphorical drain at the bottom of the bathtub to increase the speed at which CO2 can be removed. CDR differentiates from carbon capture and storage (CCS), which focuses on preventing emissions at their source. CDR, on the other hand, involves capturing CO2 from the air using various techniques.

Planting and protecting forests, a popular approach, is currently one of the more affordable CDR methods. Not only does it capture CO2, but it also provides additional benefits. However, verifying forest-based carbon offsets has proven difficult, and trees have a limited lifespan. Most models predicting warming limits also assume the development of more permanent carbon storage methods. For example, rock weathering involves accelerating the reaction between crushed rocks and CO2, while direct air capture employs chemicals to selectively bind with CO2 and remove it from the atmosphere.

Each of these techniques carries different costs and is still in the early stages of development. There is concern that relying heavily on carbon removal might discourage efforts to reduce emissions at their source. However, it appears that large-scale carbon removal has already become an integral part of climate plans. The U.S. government's net zero strategy aims to remove 500 million metric tons of CO2 by 2050, starting from a baseline of zero today. Models projecting warming limitations of 1.5 degrees envision approximately 3.8 billion tons of annual permanent carbon removal globally.

So, is this wishful thinking or a realistic view of what can be achieved in 30 years if we embrace the learning curve now? We have a strong history of developing technologies and driving down costs. Solar photovoltaic (PV) prices, for instance, have plummeted from around $70 per watt in the 1970s to $0.07 per watt or even lower today, achieving price parity with fossil fuels. However, unlike renewable energy that provides energy, CDR faces challenges regarding its demand and customer base. Major companies such as Stripe, Meta, Alphabet, McKinsey, and Microsoft have committed to purchasing carbon dioxide removal as part of their corporate social responsibility plans.

In the long run, carbon removal could become a public service akin to how we manage other forms of pollution. Governments are already offering substantial funding to establish a direct air capture industry. It is sensible for countries that have heavily relied on fossil fuels to explore the scalability of CDR. However, if it doesn't prove viable, the pursuit of net zero may become nothing more than deferring the issue once again, leading us to the same position we find ourselves in today.