When politicians talk about reaching “net zero” emissions, they’re often counting on trees or technology that can pull carbon dioxide out of the air. What they don’t mention is just how much these proposals or geoengineering would cost to allow the world to continue burning fossil fuels. There are many proposals for removing carbon dioxide, but most make differences only at the edges, and carbon dioxide concentrations in the atmosphere have continued to increase relentlessly, even through the pandemic.
I’ve been working on climate change for over four decades. Let’s take a minute to come to grips with some of the rhetoric around climate change and clear the air, so to speak.What’s causing climate change? As has been well established now for several decades, the global climate is changing, and that change is caused by human activities. When fossil fuels are burned for energy or used in transportation, they release carbon dioxide – a greenhouse gas that is the main cause of global heating. Carbon dioxide stays in the atmosphere for centuries. As more carbon dioxide is added, its increasing concentration acts like a blanket, trapping energy near Earth’s surface that would otherwise escape into space. When the amount of energy arriving from the sun exceeds the amount of energy radiating back into space, the climate heats up. Some of that energy increases temperatures, and some increases evaporation and fuels storms and rains. Because of these changes in atmospheric composition, the planet has warmed by an estimated 1.1 degrees Celsius (2 F) since about 1880 and is well on the way to 1.5 C (2.7 F), which was highlighted as a goal not to be crossed if possible by the Paris Agreement. With the global heating and gradual increases in temperature have come increases in all kinds of weather and climate extremes, from flooding to drought and heat waves, that cause h …