Climate Solutions Overview

When we think of Greenhouse Gasses (GHG) emissions, most of us think of carbon dioxide (CO2) produced by burning fossil fuels. This is for good reason: we emit more CO2 than any other GHG; and once emitted, CO2 remains in the atmosphere, trapping heat, far longer than most GHGs. But methane (CH4), nitrous oxide (N2O) and various fluorinated gasses (F-gasses) all play a role in warming our atmosphere.

[Data from IPCC Fifth Assessment Report, Working Group Three. Graphic based on one by Dr. Jonathan Foley.]

In addition to the gasses shown in this chart, black carbon particles (for example, soot from burning wood) also contribute to warming. To solve climate change, we will need to address all of these emissions, not just CO2.

With the exception of most F-gasses, all of the GHGs in this chart are natural parts of earth’s biochemical cycles. That means that long before human beings came on the scene, natural processes produced some of these gasses; and natural processes absorbed them, in turn, into land and ocean “sinks” which took and kept them out of the atmosphere. Human beings have added a lot to these natural emissions, and we’ve also degraded the capacity of natural sinks to absorb them. But the sinks are still there, absorbing about 41% of each year’s emissions. 

Credit: Project Drawdown. Source: IPCC (2014) and Global Carbon Project (2019)

To stabilize the planet, we need to bring emissions and sinks back into balance. There are two ways to do this: we can reduce emissions; and we can support existing sinks and create new ones. We need to do both.

⇒For an illuminating account of how we can fit these pieces together, read this great article by the Executive Director of Project Drawdown, Dr. Jonathan Foley: “We Need Four Waves of Climate Action.”  

How do we reduce emissions? A first step is to understand where they come from. The chart below shows global GHG emissions, with the relative amounts of different gasses other than CO2 represented in terms of their CO2-equivalent (CO2eq).

Source: Hannah Ritchie, Max Roser and Pablo Rosado (2020), “CO₂ and Greenhouse Gas Emissions,”

It’s pretty clear that the energy sector is the biggest. But we don’t have the luxury of concentrating only in one place. We need to do everything. 

⇒For an excellent overview of the whole space of climate solutions, download The Drawdown Review from Project Drawdown. This is a short, systematic, view-from-30,000-feet survey of the solutions that the book, Drawdown, describes individually. It’s a great complement to the book — in fact, you might want to read it first, before diving into the details that the book offers.

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