Yeah But… It Was Cold Yesterday

Yeah, but it was cold yesterday. It snowed. I had to scrape ice off my windscreen. Explain that, climate man!

This one turns up in comments on my socials often, usually accompanied by a smirk and a photo of snow falling somewhere. And every time it does, it reveals the same basic mistake that climate change delialists make: conflating weather with climate, and then pretending that it's a clever rebuttal.

So let’s deal with it.

Weather is what happens today, this week, or this season, in one place. Climate is what the weather does on average, over decades, across the whole planet. If that distinction feels abstract, here’s a simpler way to think about it.

Climate change loads the dice. When you roll a pair of dice, you can still roll a one or two. But if someone quietly adds weight to the sixes, you’ll start seeing more high numbers over time. The occasional low roll doesn’t prove the dice aren’t loaded. It’s exactly what you’d expect.

That’s what global warming does to the climate system. It doesn’t eliminate cold days. It shifts the odds.

If global warming weren’t happening, you’d expect global average temperatures over the last 40 or 50 years to wobble around without a clear direction. Instead, we see a long, unmistakable upward trend - not just at the surface, but in the oceans, the atmosphere, melting ice, rising seas, and shifting ecosystems. That’s the data. Not yesterday’s forecast or today's weather.

But here’s the part that really seems to scramble people’s brains: a warming planet can still produce intense cold weather. Sometimes, it can even make certain cold events more disruptive. Why? Because the climate system isn’t a simple thermostat.

The Arctic is warming much faster than the rest of the world - a phenomenon known as Arctic amplification. That matters because the temperature difference between the poles and the mid-latitudes helps drive polar vortexes, high-altitude rivers of air that steer weather systems.

And for Australians, this isn’t just an Arctic story. We sit right above Antarctica and the Southern Ocean, and the winds and pressure systems that circle the frozen continent play a major role in shaping our weather. When those big southern patterns shift or slow down, Australia feels it - in where our storm tracks run, how long high-pressure systems sit over our continent, and how long particular weather conditions hang around.

As the temperature contrast between the poles and the Equator weakens, the polar vortexes can become slower and more wobbly. Instead of zipping around the poles neatly, they can meander, bulge, and stall. When that happens, cold air can surge away from the poles and linger. Hot air can sit in place and bake regions for days or weeks. Rain systems can park themselves and dump extraordinary amounts of water.

So when someone says, “It was freezing yesterday - where’s your global warming now?”, the answer is: possibly right there!

So if someone genuinely wants to claim global warming isn’t occurring, they need to grapple with the full body of evidence: long-term global temperature records, physical measurements of ocean heat, ice mass loss, sea-level rise, and the basic physics of greenhouse gases - understood for well over a century. A screenshot of a weather app won’t cut it.

So yes, winter still exists. Snow still falls. Cold air still moves around the planet. None of that contradicts climate science. What’s changing is the balance of probabilities. The extremes are getting more extreme. The systems are getting more erratic. And the impacts are getting harder to manage, especially for the people least responsible for loading the dice in the first place.

“Yeah, but it was cold yesterday” isn’t an argument. It’s a refusal to zoom out and see the whole picture. And in a world where the dice are increasingly loaded, it's the most dangerous thing you can do.

Yeah But it was cold yesterday!