The comforting but dangerous fantasy of ‘normal’ climatic and political aberrations

“Climate has varied naturally for many millions of years, before any humans were on the planet.”

If you’re a climate scientist, you’ve heard such statements many times before. Natural climate changes over deep time are frequently invoked as “evidence” that human activity can’t possibly have caused global warming of 1.4 degrees Celsius since the Industrial Revolution. Following this fallacious logic, the existence of past natural changes in Earth’s climate means that current and future changes must also be natural.

This interpretation of reality can be comforting, particularly in light of the large and accelerating climatic changes over recent decades. It is also convenient if your business and financial interests depend on the continued burning of fossil fuels. But “all climate change is natural” is a demonstrably false and dangerous illusion.

Scientists understand the pacemaker of natural, deep-time changes in Earth’s climate. They’ve learned about variations in Earth’s orbit around the Sun. They know that there are small irregularities in this orbital path, and in the tilt and gyroscopic wobble of the Earth’s spin axis, on timescales ranging from tens of thousands to hundreds of thousands of years.

Scientists study how these small orbital variations affect the amount and distribution of sunlight on Earth’s surface, and thereby affect Earth’s climate. They’ve learned that orbitally driven changes in sunlight affect global ocean temperature, phytoplankton growth, and sea level. They know that, in turn, such ocean changes influence the ocean’s uptake and release of carbon, thereby modulating levels of carbon dioxide and other greenhouse gases in the atmosphere. They’ve figured out that on Ice Age timescales, carbon dioxide is actually a feedback mechanism that amplifies orbitally-driven temperature changes.

Scientists are familiar with this slow, stately Ice Age waltz—a dance in which the orbital variations are the leading partner, and climate and carbon dioxide follow the lead. While some details of the Ice Age waltz are as yet unclear, the basic rhythm and pattern of the dance is well-understood.

Since the mid-1800s, however, humanity has been performing a very different dance: the fast greenhouse tango. The effects of Earth’s slow orbital variations on climate are trivial compared to the effects of human emissions on climate during the industrial era. Gradual orbital fluctuations are simply incapable of producing the fast climate change caused by the new dance. Human-caused fossil fuel burning is the leading partner in the fast greenhouse tango. This tango has changed the chemical composition of Earth’s atmosphere, increasing levels of atmospheric carbon dioxide from roughly 280 parts per million in the 1850s to nearly 425 parts per million today. By ratcheting up levels of carbon dioxide and other heat-trapping greenhouse gases, humans lead the dance. Earth’s climate now follows our lead.

Let’s put some numbers to this metaphor.

The rate of warming from the end of the last ice age was about 7 degrees Celsius over a period of 18,000 years, or 0.04 degrees Celsius per century. In contrast, the rate of warming over the past 100 years was roughly 1.3 degrees Celsius per century. That’s about 32 times faster than the rate coming out of the Last Glacial Maximum. If the tempo of a typical slow waltz is 90 beats per minute, then the rate of the tango would need to be nearly 2880 beats per minute. That would be one ripping tango!

The story of how scientists have learned about the slow Ice Age waltz and the fast greenhouse tango is rich and complex. There were the early 19th century pioneers who first studied the heat-trapping properties of greenhouse gases, and who first understood that burning fossil fuels could increase carbon dioxide levels in the atmosphere. There were the scientists who, in elegant chemical detective work, figured out that fossil fuel burning produced distinctive signatures in lighter and heavier isotopes of carbon. There were analysts who then used mass spectrometry to measure these carbon isotopes, and who learned that roughly 75 percent of the carbon dioxide we’ve added to the atmosphere is from fossil fuel burning.

Other scientists built the first computer models of the climate system and made testable predictions of the climate response to rising carbon dioxide—predictions later shown to be in agreement with observations. Remote sensing experts found clever ways to measure global changes in temperature, moisture, sea level, clouds, and greenhouse gases from space. Data specialists compiled records of surface temperature change from millions of thermometer measurements at thousands of locations, or probed temperature changes in the depths of the world’s oceans.

There were paleoclimatologists who unlocked the secrets of the “proxies” that contain imprints of Earth’s climatic history: ice cores, tree rings, corals, and the abundance of pollen in sediment cores. There were theoreticians who built foundational understanding of the general circulation of Earth’s atmosphere and oceans. There were scientists who used pattern recognition methods to identify human fingerprints in observational climate records. Physicists, chemists, biologists, mathematicians, statisticians, computer scientists, social scientists, and many others—all contributed to piecing together the story of the Ice Age waltz and the greenhouse tango.

Collectively, we need to get better at telling this story. We can’t let the remarkable discoveries noted above be replaced by the false narrative that the slow Ice Age waltz disproves the reality of the fast greenhouse tango.

We can’t let mature science be drowned out by the wacky argument that a snowball on the floor of the US Senate invalidates the existence of human-caused climate change. We can’t be quiet when the president of the United States egregiously dismisses climate change as “the greatest con job ever perpetrated on the world”. We can’t let the deeply-flawed report released this summer by the US Department of Energy—a report that resurrects false arguments that have been debunked for decades in the peer-reviewed literature—be used as justification for weakening legal protections for clean air and clean water. We can’t let critical climate monitoring capabilities be destroyed. We can’t let state-sponsored denial of robust scientific evidence continue to spread unchecked.

In today’s United States of America, chaos and disinformation are the new normal, and attacks on science and democratic principles spew from the same ideological fount. Thousands of government climate scientists have been fired. Research grants that do not comport with the president’s political agenda have been suspended. USAID was fed to the woodchipper. Panels of vaccine experts were disbanded. “Climate change” is now a banned phrase within certain federal agencies. History is being erased at museums and in National Parks. The National Guard has been deployed in US cities against US citizens. Masked ICE agents sweep people off the streets (including American citizens), drag people out of their cars, and raid apartment buildings. The Justice Department is investigating citizens deemed to be enemies of the president. The US National Academies of Science, Engineering, and Medicine are under Congressional scrutiny for trying to establish “whether greenhouse gas emissions are reasonably anticipated to endanger public health and welfare” in the United States. The Department of Defense becomes the Department of War. The Supreme Court ruled that “official acts” of an incumbent President, no matter how reprehensible, are not crimes. Kindness and compassion for the less fortunate are eradicated from government policy.

As with the obviously fallacious argument that the slow Ice Age waltz disproves the fast greenhouse tango, it can be tempting to assume that the present-day events listed above are not unusual in the context of the long political history of the United States. It can be tempting to develop a narrative that what we’ve experienced since January 2025 is only a temporary aberration in the turbulent story of our democracy, no worse than prior political aberrations.

That is dangerous. Our current political climate is just as unusual and concerning as the current state of our planetary climate. In both cases, we no longer need sophisticated signal identification methods to tell us what Hamlet knew—that “the time is out of joint.” It’s up to all of us to set things right.