My why for climate action

I want to start my climate series with why I think it’s the issue of our time.

The short version of my argument is that there’s no other issue within humanity’s control that affects the wellbeing of so many living things and requires immediate action at every level of society, from the global stage to the kitchen table, with the clearest scientific understanding of cause and consequence. Sure, a giant asteroid may strike the earth and AI may fundamentally upend society (or worse), but the former is largely out of our hands and the latter isn’t well understood even by experts.

It’s the longer version of my argument—several posts exploring how I think about the climate crisis, how I feel about it, and what I’m doing about it—that diverges from common climate narratives. Most of what I hope to share has been well stated elsewhere within the climate community, but I find that the best climate arguments get lost amidst the worst climate arguments, to the detriment of general understanding and across the spectrum of climate concern. We all deserve the best version of the argument, and I think we’re most likely to hear it when it’s coming from someone we know rather than an unknown expert.

Our Goldilocks climate

Let’s start with some history: in its 4.5 billion years of spinning around the sun, our planet has undergone dramatic swings in temperature.

The last time Earth’s global average temperature was this hot over a sustained period of time was at least 125,000 years ago, long before the dawn of human civilization. But it’s been much hotter. Some fifty million years ago, global average temperatures were 5–8°C (9–14˚F) warmer than they are today. Palm trees, ferns, and reptiles lived above the Arctic Circle. Antarctica was covered in temperate rainforest. The oceans were so acidic that many marine species went extinct, and any inland mammal larger than a rat struggled with heat regulation.

It has also been cooler. The last ice age occurred about 20,000 years ago, and studies suggest that global temperatures averaged 6˚C (11˚F) cooler than those of today. That may not seem like much, but it was enough to cover most of North America and Europe in ice sheets up to two miles thick. Sea levels were about 400 feet lower than they are today, with coastlines existing dozens to hundreds of miles from their current positions. Such is the power of relatively small changes in global temperature, extended over long periods of time.

By contrast, human civilization has evolved within an unusually stable climate period. For most of the last 12,000 years, average global temperature has been remarkably steady, generally remaining within a range of 0.5–1°C (1–2˚F).

It’s argued that this stability made it easier for humans to settle in one place, develop agriculture, and create complex civilizations with specialized roles. What it undeniably did was shape our sense of what was normal and where to sensibly place things—not only coastal settlements and trade ports, but also agricultural regions, reservoirs, and other critical infrastructure. And we weren’t the only ones optimizing around this stability: plants and animals did, too. All of Earth’s creatures have placed bets on this normalcy—literally trillions of lives and trillions of dollars invested in a Goldilocks climate: not too hot, not too cold, just right.

But for the last hundred-odd years, our planet has gotten warmer, and at increasingly fast rates:

Source: Wikipedia

Since 1970, the Earth’s temperature has spiked faster than in any comparable forty-year period in recorded history. The last ten years were the warmest years on record (source: NASA), and 2024 was the first year to exceed the 2˚C target set by the Paris Agreement, to which all but four countries (Iran, Libya, Yemen, and the United States) are committed under international law.

What’s in a few degrees?

How concerned should we be about a few degrees, or even a few tenths of a degree? Should these targets even have a bearing on what we do now? These are all fair questions.

Signed in 2016, the Paris Agreement aims to limit global average temperature to less than 2.0˚C above the pre-industrial average, with a stretch goal of limiting to 1.5˚C. Before this agreement, most “business as usual” projections showed the global average temperature increasing by ≈4˚C by 2100. Contrary to doomer imagination, this scenario probably wouldn’t send humanity into a Mad Max hellscape, but it’s not a world I want to live in:

• The Great Barrier Reef (along with most/all other coral reefs) would experience severe, possibly irreversible coral bleaching and risk of ecological collapse.
• The Himalayan glaciers would be severely depleted, exposing approximately two billion people to chronic water shortages.
• Decreasing crop yields and increasing heat waves would trigger a massive human exodus from the tropics—the largest human migration in history.
• Feedback loops and tipping points would threaten to shift planetary systems even further out of our favor and make it harder for all living things to adapt.

In short, life as we know it would be destabilized to an unprecedented degree, and countless living things and living systems would die. It’s a scenario that the World Bank said “simply must not be allowed to occur.”

Thankfully, we’ve stepped off the 4˚ path. Based on implemented policies and outstanding pledges, most models now predict warming somewhere in the 2–3˚ range by 2100. But the best climate outcome would be staying within the 0.5–1˚C range that, until the last ten years, was all human civilization had ever known.

This is the context in which to frame the Paris targets: the 2˚C target is the global order’s estimation of what’s needed to protect their status quo. The 1.5˚C stretch goal doesn’t represent an ecological ideal; it was the limit of what was considered politically possible, a nod to those for whom an additional 0.5˚ of warming could mean the difference between having a nation and not—between at-risk species existing, and not. Which I think underscores the cruel reality of climate change: its effects aren’t evenly distributed, those least responsible for it are most vulnerable, and the warmer it gets, the more appalling this disparity will be.

You’ll be fine; others won’t be

The 2–3˚C projection represents a spectrum of outcomes in which you’ll likely be fine, but the most vulnerable among us—those who’ve contributed the least to global warming—will be strained to the brink.

When I say “fine,” I mean that you, as one of the global rich, will probably get along. Your summers will stretch longer and have more days where it’s unsafe for children to play outside. You’ll check air quality apps the way you used to check the weather, canceling plans when smoke from distant wildfires turns the sky orange. You’ll pay significantly more for coffee and chocolate (even after adjusting for inflation) as traditional growing regions fail. You’ll scroll through news of (hopefully distant, hopefully not global) conflicts brought on by human migration, water rights, and regional food shortages. Your children will ask you why you didn’t do anything when scientists first sounded the alarm decades earlier. You’ll learn what it felt like to see passenger pigeons vanish from the sky, to watch bison vanish from the plains. You and the rest of the global rich will adapt, but in a world of diminishing vibrancy and foreclosed possibility, tinged with generational regret.

Some will be luckier than others, just as it has always been. Adapting will be easier for Paris than it will be for Jakarta. Birds will have more migratory options than elephants will. Polar bears and bristlecone pines will have nowhere to go. Entire species and island nations will succumb to a climate that no longer supports their existence.

From climate anxiety to climate purpose

A common criticism of the climate movement is that it’s a religion and that it portrays a warming planet as a sort of secular end times. You don’t have to look hard to find people who unwittingly reinforce this narrative; I suspect there’s something in human psychology that is easily seduced by apocalyptic thinking.

I take a different view: a warmer planet won’t be the end of the world. It won’t be the end of human civilization or even the end of material progress. But it might be the end of a normalcy that future generations will view as comparatively equitable and grossly undervalued.

To bring it back to an earlier question, do these minute differences in global temperature even matter? Yes, they do: every increment matters to those at the margins. This is daunting, but also invigorating: anyone who cares about climate change can help steer the world toward better outcomes by reducing emissions faster than if we rely on policy and technology alone. There are things we all can do to accelerate the pace of progress: this doesn’t involve spurning straws or carefully recycling yogurt containers; it doesn’t require any one particular action at all. What it does require is urgency, which is what I hope to explore in my next post.