I don't argue that humans impact climate change... But I do want to mention that around 3000BC the world was roughly 2°C warmer, which is what most climatologist claim we will be at after we continue to burn fossil fuels (until we probably run out)
Overall, this isn't "random chance", but it's also probably happened before within the span of human existence. The world changes and I am sure the world will adapt, and while that happens mass extinctions and horrible growing pains will likely occur
Woah woah woah, the 2° C scenario is definitely not what happens if we burn all remaining fossil fuels. IPCC's A1FI scenario which more or less describes that 'plan' (A1FI actually still predicts an eventual transition to renewables...) has a predicted temperature increase of 2.4 - 6.4° C.
2°C is what the Paris Accords expect us to get with significant changes. We're already at 1.3° C.
You can't really make that claim yet. The sun is also at the peak of it's 30 year output cycle (and I believe there's also a greater cycle as well). We can't know the full effect for decades probably. Which is kind of the point of my statement.
We can freak out all we want, but the world will survive and the world (probably humanity) has faced much harder times with much worse technology.
Sure, but atmospheric CO2 concentrations haven't been this high in anywhere from a million to twenty five million years. Coral reef death is as much related to ocean acidification as it is to temperature increase.
And it's very easy to write off the effects of climate change as "horrible growing pains," but to be concrete about it: you're talking about the deaths of potentially millions of people. This is a moral issue on par with Auschwitz or the Gulag. And while you're free to shrug your shoulders with, "well, shit happens," it's silly to act as if people concerned about it are histrionic tree huggers.
Instead of self-imposing pseudo-malthusian constraints, why can't we just embrace the fact that we are geo-engineering on a massive scale and actively do it instead of the accidental kind we have right now? It would only take an increase in tree biomass of 1.5% to offset human CO2 production. Phytoplankton stimulation would be an incredibly cost effective method to counteract human industrial activity yet why is it completely ignored in favor of regulating everything and constraining progress?
As far as trees go, how many decades can you increase tree biomass continuously 1.5% year on year? Where does the extra land to do this come from? How do we build new land that can effectively grow new trees? It's fine, as far as it goes, but we'll run out of trees to plant long before we run out of fossil fuels to burn.
Phytoplankton stimulation is a lot better, in that we can do it year on year. Indeed, it can, optimistically, remove around a billion tons of CO2 per year from the atmosphere, with advancements in technique and extremely widespread use, for a relatively low cost.
Humans emit roughly 40 billion tons of CO2 per year into the atmosphere, though. Year on year, we add roughly a billion tons of CO2 emissions to our annual emission rate.
We can go into even more exotic methods if you like. But if governments are unable to implement a tax on carbon that accounts for its externalities, why do you think governments would be willing to pony up even more money to sequester those externalities after the fact?
This xkcd comic is based in poor data, probably. Rats and domestic mice don't appear on it. Cats and dogs should appear also (and be in a big group). I would take it with a pinch of salt.
Personally I think it'd be better if we all adjusted our lifestyles to reduce our affect on the planet, but I just don't expect that to happen. Geo-engineering seems like a worse solution which is far more feasible to actually get done.
Geoengineering is such a dangerous (both morally and in terms of its possible consequences) approach that it shouldn't seriously be considered as an option.
Cfr. [1] for its possible consequences in Asia and Africa:
Both tropical and Arctic SO2 injection would disrupt the Asian and African
summer monsoons, reducing precipitation to the food supply for billions of people.
These regional climate anomalies are but one of many
reasons that argue against the implementation of this kind of geoengineering.
How will climate change cause millions of people to die? Honest question.
I thought most of the damage would be monetary via mass relocation. Are those deaths preventable outside of human behavioral change to keep temperatures lower?
You say mass relocation like it's a vacation to the French Riviera.
Within developed countries, climate change will be costly but not particularly deadly. A few more heat exhaustion deaths, a few fewer cold-related deaths, and it all balances it. If anything, climate change will be good for mortality in developed countries, because cold kills a whole lot more people than heat now. Remediating the effects of climate change will be very expensive, on the other hand, and I buy the equation that throwing away money is throwing away lives, but let's leave that aside for now.
The big issue is in developing countries. All of them are exceptionally vulnerable to climate change, since they're nearer the equator; all of them have severely resource-constrained economies; all of them have less stable political cultures and are more likely to go to war with nearby neighbors; most of them have megalopolises built in areas susceptible to climate change. Mass relocation just simply isn't in the cards for them.
Dhaka is a couple meters above sea level on average: what happens when the sea level rises by a meter? I remind you that it's a city of around 20 million people, and the rich tend to live in higher elevations than the poorest, densest areas. Where do they go? Does Bangladesh go through a massive infrastructure project to build Netherlands-scale dikes? Who pays for it? Donald Trump? Or maybe the USA and Europe open their doors to millions of Muslim immigrants from Bangladesh alone?
Dhaka is an extreme case, but this story replays itself all over. And there are other factors to account for: increase malaria prevalence by 10% and you've killed 50k/year. These things add up. And of course you can say, "well, sure, but you can use money to save these lives!" But if we're utterly unwilling to bear any costs of our pollution now, why would we be willing to in 2100? Our grandchildren might fairly say, well, it was our asshole grandparents who selfishly shat all over the world, why should we have to suffer exceptionally for it?
>Our grandchildren might fairly say, well, it was our asshole grandparents who selfishly shat all over the world, why should we have to suffer exceptionally for it?
You know, we young folks are right here. We are already suffering and already angry. We already want the maximum preventative and ameliorative efforts taken.
Turns out the sun has more to do with global temperatures than just about anything. I don't know if it's in one of those lectures (it should be), but the sun had a pretty hot 1000 years there where it also released more radiation. This actually impacts radiocarbon dating.
You do realize that taking historic temperatures are pretty difficult and we can only get an approximation? Meaning, you may only get the historic average over a given 5, 10, 50 years when looking at historic data. Meaning some years may have been 5°c warmer on average, while others were 5°c lower on average. We simply can't know.
Regarsless, the point of my comment is still relevant. This has happened before, it will happen again. We should try and minimize damage, but also keep the perspective that in the past tempratures have fluctuated more and faster. It's been warmer and colder on our planet, and everything will adapt.
> Meaning some years may have been 5°c warmer on average, while others were 5°c lower on average
yeah, I'm going to go out on a limb and guess you haven't done a lot of research on this. Short of super volcano winter you aren't going to see more than a tenth of that in annual variation.
> Regarsless, the point of my comment is still relevant
No, it's really not. Not only was your initial claim wrong, but your point seems to just be that "changes happen", which is vacuous in and of itself.
Some day we'll reach the heat death of the universe. Why do anything at all, am I right?
> yeah, I'm going to go out on a limb and guess you haven't done a lot of research on this. Short of super volcano winter you aren't going to see more than a tenth of that in annual variation.
You'd be wrong, I have done a lot of research. The fact is, we can only sample averages based on decades at a time. Meaning, even if a temperature is (like I said) 5°c warmer in year 1, then 0.5°c cooler until year 20, then rise again 0.5°c for the next 10 years, the gaussian of the sample would put the temperature is roughly 2.5°c cooler than today for that 30 year window.
You have to look at how this data is gathered, it's through melting ice mostly. Which is not an exceptionally accurate measurement.
And all my points have been the same (before a bunch of people came and down voted), life will go on and this is normal. Extinction events happen every few thousand years. Yes we are the cause, and no I don't think we shouldn't do anything. However, I also don't think we should ignore the fact that historically this isn't rare.
>>But I do want to mention that around 3000BC the world was roughly 2°C warmer
The question you have to ask yourself isn't necessarily absolute temperature, but rather the rate at which such temperature fluctuations occurred in the past. Lots of species may be able to adapt to the planet becoming 2 degrees warmer over the course of 100,000 years. The overwhelming majority can't adapt if such changes occur over the course of 100 years - which is what we are seeing now.
If that was true then you'd expect an El Nino to cause mass extinction. You can get > 2 degree warming over massive areas of the globe during an El Nino year.
2 Degrees warming over some areas. Global warming causes 2 degrees warming across the world on average, that means much more than 2 degree in many places.
Not that that is the case here because 1. It's about ocean temperatures and 2. Coral reefs are highly susceptible to small changes.
"around 3000BC" the temperature change 2 degrees in < 200 years? Because it is definitely not just a temperature change, but a rapid temperature change that is the issue.
Historically, there have been much larger and quicker changes in temperature, such as when a super volcano erupts. The whole point of my original comment was to point out that yes we (as humans) are causing issues and yes we should try to mitigate said issues, but at the same time keep a perspective. Based on what we know, this is not really rare in the history of our planet.
Overall, this isn't "random chance", but it's also probably happened before within the span of human existence. The world changes and I am sure the world will adapt, and while that happens mass extinctions and horrible growing pains will likely occur