Everyone likes to talk about the weather. It affects all of us, it’s always happening, and it’s uncontroversial — not like third rails of polite company such as politics, religion, or money. So when you spend the holidays with extended family, one of your relatives who denies the reality of climate science may see a little snow as an easy opportunity try to land a non-political jab about climate change. Or global warming. Whatever those hippies are calling it these days.
It’s easy to get blindsided, so here are some key points to help everyone stick to the facts, and ensure you don’t spend the holidays caught in a morass of climate denial just because it’s snowing.
Just because it’s cold right now in the place where you live does not disprove basic climate science
“How can there be global warming, it’s so cold out?” asks Grandma. “Global warming, am I right?” shouts Uncle Bob from the porch as you shovel off the driveway. This is one of the most common misconceptions about climate change. If someone tries to disprove decades and decades of climate science by pointing to abnormally cold weather, agree that yes, sometimes it gets cold. Whether it’s called climate change or global warming, it does not mean that cold weather will just stop happening.
Weather is not climate any more than an one ocean wave is not the same as the tide. To understand what’s really happening to the climate, you have to gather a lot of data points (weather) together over a period of decades or centuries and look at the trend. You’ll find that there have been fewer cold records and more hot records. Though this year in the U.S. there has been a big spike in cold records, the larger trend is for more extremely hot days.
But the biggest and most difficult point is that climate change is about what is happening to the whole world — it’s why they call it global warming and not Des Moines warming. It is almost a certainty at this point that the year 2014 will be officially known as the hottest year on record, after the world saw its hottest April (tie), spring, May, June, August, September, and October, according to independent analyses from the world’s top meteorological organizations. NOAA said the 12 months between October of 2013 and September 2014 were the hottest on record. And all this with less and less likelihood of an El Niño effect, the ocean temperature cycle that historically has accompanied the hottest years we’ve ever seen.
Isn’t it more amazing, and alarming, that climate change is so relentless that the world is probably going to see its hottest year on record even with the U.S. getting creamed by a weird jet stream, Polar Vortex, Arctic Outbreak, or the fact that the Bills and the Jets had to play in Detroit because Buffalo got snowed out?
There is no “pause” in global warming
Uncle Bob keeps at it. “Hasn’t it not warmed in the last 16 years?” he asks you while pulling the turkey out of the oven. “I heard something about a pause in global warming.” This is a very common talking point from climate deniers and those that share their skepticism — that there has not been any global warming since 1998. The reason that 1998 was so hot was because it was a very strong El Niño year, which boosted its already-rising average temperature extremely high relative to the broader trend. But there have been hotter years on record, and they’ve all come after 1998.
Annual temperature anomalies and 2014 projection from NOAA (see below). Click to Enlarge
Much of the heat that gets trapped in the atmosphere by greenhouse gases ends up in the oceans — 90 percent, in fact, according to recent studies. Taking this into account, global warming has dramatically accelerated over the last 15 years, no matter what “pause” graph Uncle Bob shows the cousins on his smartphone.
“Global warming,” “climate change,” call it whatever you want
Some people claim that it used to be called global warming, and once that became inconvenient, the name changed to climate change. NASA explains that it took several decades for the scientific community, and the world at large, to decide how best to describe the effect that greenhouse gases would have on the Earth, in combination with other factors. But for quite a while now it’s been clear that not only will this cause more heat to be trapped in the atmosphere and oceans, it will also bring sea level rise and drastic changes to precipitation patterns. So simply calling it global warming does not adequately describe what is happening to our world. It wasn’t a trick, or a compromise — you can still call it global warming if that is easier.
There is no conspiracy, and there is broad consensus that climate change is happening
Uncle Bob might bring up the argument that the data can’t be trusted, or that there’s a big debate over whether the world is actually warming. Scientists are always trying to prove each other wrong — it’s the competitive byproduct of the scientific method. Each finding gets tested and challenged and refined by peers and competitors. Outlandish claims get even more scrutiny, and so when climate science was advancing, there were lots of people trying to prove them wrong. If there was bogus data at this point in the process, any of the world’s top climate scientists would want to be the one to find this out and take credit for being the one to do so. That would be huge news (and a sigh of relief to those so concerned about the problem). But through the rigorous peer review process, this data, these studies, this body of knowledge have been through the ringer and back, and have come out more robust each time. Investigations into faux-scandals like “Climategate” (where researchers’ hacked emails got released to the public and taken out of context) all cleared the researchers of any wrongdoing or impropriety.
Every major scientific society in the world has agreed that climate change is happening and human greenhouse gas emissions are causing it. And 97 percent of climate scientists agree. They are 95 percent certain in fact, which is the same level of certainty that the universe is 13.7 billion years old, vitamins are good for you, and dioxin is bad for you.
Yes, we are causing it
“The world is so big, there’s no way we can change the weather just by burning coal and oil,” says Uncle Bob later, at the dinner table. Aunt Stella join in, saying that the climate has changed before, how can we know that this is because of us? Feel free to bring up that same 97 percent scientific consensus that climate change is happening, because they also have concluded that it’s due to human-cause carbon pollution. But experts have looked at this, and there’s only one real conclusion: this warming is not natural. They can test that carbon dioxide chemically, and they know it’s coming from us. CO2 levels have continued upward — just this year, we had the highest CO2 levels in 800,000 years. And we know that it’s not just a natural force like the sun getting warmer — the lower atmosphere is warming while the middle atmosphere is cooling. This can only mean that heat that would otherwise exit the Earth is getting trapped by greenhouse gases.
It’s not about whether you want warmer or cooler days, it’s affecting all of us right now
Evidence mounting, Uncle Bob and Grandma cave a little, admitting that “even if you’re right, wouldn’t a warmer world be nicer?”
It might be, sometimes, in some places. But a lot more places will face extreme flooding, storm surge, drought, downpours, heat waves, and storms. The EPA says that “climate change could affect human health, infrastructure, and transportation systems, as well as energy, food, and water supplies.”
Teenagers today have not seen a colder-than-average month in their entire lives. And at the rate humans are spewing carbon emissions into the atmosphere, they are locked into 4 degrees Celsius of warming by the time they are in their 80s, according to a recent report from the World Bank. Two degrees of warming is the level most scientists have set as the limit we can adapt to without suffering truly catastrophic consequences.
And just look around the dinner table for examples. Climate impacts are already threatening turkey, corn, pecan pie, pumpkin pie, wine, green beans, cranberry sauce, sweet potatoes, stuffing, and mashed potatoes.
If your polite, factual contributions to the conversation have opened some minds to the reality of climate change, why not see if you can engage in a productive conversation on what to do about it? You can read how to do that here.