Throughout Earth’s history, the composition of the atmosphere has been foundational to Earth’s suitability for life, writes Tom Chi.
We see the too-thin atmosphere of Mars and too-thick atmosphere of Venus as cautionary examples where runaway atmospheric processes have created inhospitable planets of once promising places.
In previous instantiations of our own atmosphere, the lack of an ozone layer prevented any life on land for billions of years. Fluctuations in Carbon Dioxide levels have driven periods where Earth’s surface fully froze over (iceball Earth), as well as periods where our planet had no ice caps at all (hothouse Earth).
Given this varied history, why are we so concerned at this moment?
First off, many of these changes took place over thousands to millions of years, giving life more time to adapt. Even with a longer grace period, these events drove mass extinctions which took life millions to tens of millions of years to recover from. Changing the climate at a rapid pace is a risky proposition to most of life on Earth – including us.
Secondly, the runaway process that is destabilizing Earth this time is one that we created. This gives us a huge amount of agency over the outcome.
What to focus on (emissions mix):
▸ 26% Food and Agriculture (Nitrous Oxide, Methane, Carbon Dioxide)
▸ 25% Electricity Generation (Carbon Dioxide, Methane)
▸ 21% Industrial Process Heat (Carbon Dioxide, Methane)
▸ 14% Transportation (Carbon Dioxide)
▸ 6% HVAC & Refrigerants (F-Gases, Carbon Dioxide)
▸ 8% Other
Within Food and Agriculture, the key area of focus is around protein production. Meat and Dairy uses over 77% of the land used for food production while providing only 18% of the calories in the global food system.
Within Electricity Generation, Wind and Solar have been making good strides, but we will also need baseload and grid storage to grow at appropriate pace.
Within Industrial Process Heat, materials like Steel, Cement, Aluminum, Glass, and Paper need to be produced with far lower emissions.
The energy density of batteries make them suitable for cars and light trucks, which could address roughly half the emissions from the transportation sector, but aircraft and other larger vehicles will take more time as batteries don’t perform in the right order of magnitude relative to energy density per kg and energy density per volume.
Lastly, refrigerants need to be addressed with lower impact refrigerants and devices that are able to make use of them.
The changes span a couple dozen industries, so even though the work is extensive, it is not unbridgeable. We are finding solutions every day that bring down industrial emissions dramatically – sometimes greater than 90%.
Beyond being less emitting, using less energy to achieve the same industrial outcomes saves money and will allow the industrial players that adopt these technologies first to set the tone and pace for their industries going forward.