For some reason climate change is still being debated in some circles. This may be because we live in a world where people just want to argue about literally everything no matter what it is or even why. For the purposes of our question today we’re going to take it as a fact that climate change is a real thing, and it’s going to have real consequences for you and me and everything else in the world.
Accepting climate change is a fact is one thing, but understanding what it means is quite another. People aren’t wrong when they say that the Earth has gone through periods of climate change in the past. We’ve had at least five ice ages, we’ve had periods of warming, and there’s still life on earth. Does that mean we could weather a serious climate change with little difficulty? How much climate change is too much? And, most seriously, is it possible climate change could wipe out humanity?
Those are some weighty questions and since it’s all speculative, we can’t be one hundred percent sure. But we can rely on what some experts think!
Climate vs Weather
One thing to remember is a thing deniers over overlook intentionally or otherwise. Just because it’s cold one day doesn’t mean climate change isn’t real. Climate refers to average conditions over a longer period.
If the temperature on November 1st is below freezing and that’s not normal, you can go online and arrogantly say “pfft, so much for climate change” but it misses the big picture of the fact it’s actually abnormal to be freezing on November 1. It also disregards that maybe June 1 was 10 degrees hotter than it has ever been in history. These are trends, not individual instances.
Too many people think of climate change like it’s the money in their wallet. “Hey look, I have $100, that’s awesome!” But their bank account is overdrawn and they’re actually $1,000 in debt. That $100 is weather. The debt is climate change. Big picture stuff!
Global Temperature Trends
If you’re still not 100% sure about climate change we can look at global temperature trends. Have there been warmer days in the past? Absolutely. But remember, we’re looking at trends.
Global records of temperature began in 1850, and we’ve been recording temperatures since then. As of the beginning of 2024, 2023 was the warmest year on record. It was 1.18 C above the 20th century average. These aren’t big numbers we’re dealing with across the board and that’s why we can get a freak snowstorm in late April 2023 when Spring is supposed to be springing and still experience the warmest year on record. Because later that same year, over 2,700 people in the US died and had heat-related complications listed on their death certificates. That’s a record for heat related deaths and shows that people need to focus beyond one random cold day to argue against warming temperatures when there are too many random hot days pushing the mercury in the other direction throughout the year.
The ten warmest years in recorded history were all in the past decade. That means every year is now one of the warmest years in recorded history as of 2014. It just keeps getting worse. As of November 2024 was on track to become the new warmest year on record.
By 2030, temperatures are expected to be 1.9 C to 2.7 C higher. This temperature increase has been attributed to countries like China which have seen swiftly rising emissions from fossil fuel burning over the last years. While their use is hitting a plateau, it also rose faster than anticipated.
Likewise, there is a fear that the US government may abandon any promises it made to stem emissions and combat climate change, which could see further increases across the board.
How Hot is the World Getting?
In 2016 the Paris Agreement was signed and ratified by 55 countries that agreed to reduce greenhouse emissions in order to prevent global temperatures from rising by 1.5 C above pre-Industrial levels by 2030. However, 2024 is already on track to have hit that 1.5 C marker. It’s believed this trend will continue for at least one of the next five years. In the year 2015 it was believed there was a 0% chance this would happen. Now it’s at about an 80% chance.
Since 1980, the number of places in the world that experience extreme heat events has increased 50 times. We’re not trending in a good direction.
Why 1.5C?
The 1.5 C mark didn’t come out of nowhere. There has been serious study about the potential effects of long-term global heating. So, if 2024 was 1.5 above pre-industrial levels it doesn’t necessarily mean that the world is ending. The problem is, if those temperatures are sustained over some decades. If we can’t decrease the temperature, and 1.5 Celsius above pre-industrial becomes the norm then there are various ecosystems and regions on the earth that will not be able to sustain their current conditions. Basically, we’re talking about creating deserts and destroying farmland, forests, that sort of thing.
Some people who sound fairly educated on the topic will argue that climate change is not a thing to worry about because it’s a natural part of Earth’s history. So why not take a look at some of their statements and why they may not be as accurate as climate change deniers think?
Climate Denial Arguments
If you ever get into a debate online with a climate skeptic, they will probably bring up the idea that the Earth’s climate has changed many times over history. We already mentioned ice ages and periods of warming and yes, the earth’s climate has changed many, many times in the 4 billion years this planet has been here. But that isn’t the full story.
To say there’s no need to worry because greenhouse gasses have spiked throughout history is to overlook what happened next, not to mention the fact we’re making it happen faster than it ever did naturally.
These spikes have been followed by massive ecosystem changes, species extinctions, and ice ages. The effects are long term but they are fairly consistent. Humans only focused on the next ten years won’t see or maybe even care about these longer-term effects, but history shows they are real.
Some people will also try to claim there is dissension in the science, that not all experts agree on climate change. And sure, not all experts agree, but some people will argue that the earth is flat, that doesn’t mean there’s any real debate among scientists. According to NASA, 97% of scientists still working in the field agree humans are causing climate change.
There have been stories published in the media about how climate change could have benefits like nicer, milder days in places like Canada. Again, that’s true. Canadians won’t have to endure as many harsh winters, but it kind of overlooks the bigger picture.
The consequences of climate change include things like those 2,700 deaths that we mentioned earlier. Also increased tornado activity, floods, droughts, loss of crops, species extinction, ecosystem destruction and so on. It’s even directly linked to modern slavery where those affected by climate disasters are forced into poverty and slavery to survive. So sure, you might get to enjoy a green Christmas, but when July comes around, maybe a whole town full of people on the other side of the world die because it’s over 50° C.
Trying to find a silver lining in climate change is a fool’s errand at best. It’s believed the total cost to the global economy could be around $23 trillion by 2050.
How Hot Would The World Need to Get to Be Unlivable?
So, let’s say we all agree that climate change is happening, humans are causing it, and it’s not a good scene. There are various ways to interpret that last part. We know that we’re causing the extinction of various species, serious weather events are becoming more common, and human lives are being lost as a result. But at what point does it become untenable? How hot does the world need to get before all of us are hurtling towards certain doom?
We don’t need to hunt down isolated stories of heat related deaths; they happen regularly around the world. In 2024, over 1,000 people died when temperatures hit 52° C during the hajj pilgrimage in Saudi Arabia. In Europe, about 47,000 deaths were linked to heat extremes. It’s already happening.
Research has shown that humans can only endure 31°C at 100% humidity before they can no longer regulate their temperature. That’s for young, healthy people. If you’re older or suffer any health conditions, it’s going to be lower. That means you need help to lower your temperature if it gets to that point because you can’t do it on your own, and you’ll suffer consequences including heat stroke and potentially death.
You need to remember when you look at these temperature figures that the humidity is what really causes the problem. If you live in a dry climate like Arizona, you can handle higher temperatures because you’re going to sweat and cool yourself down. If Arizona’s hottest day came with 100% humidity, you’re not sweating anything away. You’d have to endure that heat in all its glory and that could be lethal.
This temperature/humidity rating is also very subjective. If identical twins are in the same place at the same temperature, but one has been working all day, that one is going to fall victim to heat stroke sooner, and at a lower temperature or humidity. As global temperatures rise, larger areas fall into this zone for longer periods of time, making it impossible for some people to survive.
If we hit 2 degrees C above pre-industrial levels, then 2.2 billion people in the Indus River Valley throughout India and Pakistan, another billion in China and 800 million in Sub-Saharan Africa will be in that intolerable zone for extended periods every year. Add that up and that’s four billion people, or half of the entire world.
If we reach 3 C, you can expect those same conditions in the US all along the east coast and as far inland as Chicago. South America and Australia would endure the same. We’re expecting to reach that 3° by the year 2100 if we can’t turn climate change around. If we even hit 2 degrees higher by then, it’s been predicted that as many as one billion lives will be lost as a result.
If temperatures get to a consistent point between 40 C and 50 C then many species, humans included, will be unable to survive. That’s an extremely unlikely outcome on a global scale, thankfully, but it may happen in some isolated areas that will force populations to flee as a result.
Keep in mind, it’s not just the heat that we need to worry about. Melting ice causes the sea level to rise which swallows coastal cities. More hurricanes, floods, tornadoes and droughts all contribute as well.
Can Humanity Survive Global Warming?
That 1 billion deaths figure that we say that earlier is an outlier. That’s the extreme end. Some predictions are as low as 40 million. That’s like all of Canada dying, or both Michigan and Texas going out together. Now take a moment to appreciate the fact that you just heard us refer to 40 million deaths as the low end of things. That’s the best-case scenario kind of outcome and that is absolutely horrifying.
In general, few climate scientists think that climate change is going to wipe humanity off the map, but it’s also something we shouldn’t rule out entirely. We will probably endure this and we will adapt. But that doesn’t mean it’s going to be pretty, there won’t be severe consequences, and we won’t lose a lot of people along the way. It’s going to be ugly.
What we’re going to see is mass migrations to survive climate change. People who live on islands are going to be forced to flee because, as sea levels rise, islands will disappear. Tens of millions, if not hundreds of millions, of people are going to have to migrate out of the extreme temperature zones that are no longer fit for human life.
Crops are going to have to be adapted to prevent starvation and farmers will need to switch to new ones in certain places. Growing seasons will change, availability of water will change, or a dozen other factors affecting agriculture will need to be addressed all around the world.
Climate change has happened, is happening and will continue to happen. How bad it gets is only something we can guess, but here’s hoping we continue on a path towards preventing as much damage as we can.