Historically, the earth went through some wild cycles that lasted millions of years, ranging from “snowball earth” to the mostly tropical world of the Jurassic and Cretaceous. Mankind emerged in a relatively stable period, which makes one wonder what it would be like for us if the stability ends for whatever reason.
Or, you know, opening up northern sea lanes, which would reduce the energy required for worldwide shipping.
Also the conversion of millions of acres of tundra into arable land. And the reduction in heating energy in the populous and wealthy northern regions of the globe.
The truth is, moderate global warming (2C or less) may actually be a net economic benefit to the planet for these reasons and others, while still being damaging to equatorial countries and coastal regions. At some point the costs outweigh the gains, but the exact temperature at which this point is reached is really unknowable. The economy and ability of humanity to adapt to new conditions makes this a very hard thing to figure out.
That’s a very long term process though - an unfrozen tundra doesn’t magically become productive soil.
The “stop all man-made emissions tomorrow” is impossible because they would continue from various man-made sources even if we instantly stopped burning all fossil fuels, like the results of deforestation and other land use changes and the emissions of methane from a thawing Arctic. The closest approximation is the IPCC RCP 2.6 pathway which assumes a very aggressive strategy of mitigation and conversion to clean energy so that emissions start falling almost immediately.
What happens in that scenario is that CO2 levels in the atmosphere very, very slowly start falling, over the course of hundreds of years. Meanwhile feedbacks like exposed ocean and land surface areas over an already thawing Arctic will continue to provide accelerated warming in the far north for a very long time, some of that now happening in the Antarctic as well. The bad news is that stabilization of the climate will take many hundreds of years, but the good news according to models is that the most aggressive mitigation strategies approach equilibrium faster, so that RCP 2.6 would be as much as about two-thirds of the way there by 2100, and thereafter continue on a slow asymptote to a stable global temperature.
So where would we be in 2100 if we went all-out in this fashion, an unrealistic all-hands-on-deck approach that did everything we possibly could? Well, the name RCP 2.6 comes from the presumption that the best we could possibly do would result in a radiative forcing increase over the earth of +2.6 W/m[sup]2[/sup] relative to pre-industrial values. From a bit of poking around I’ve seen this associated with approximately a further 1.0 °C average global temperature rise compared to the present (though very much more or less in specific regions), about 16 inches average sea level rise, and relatively small to moderate increases in incidents of extreme weather. We’d see continuing changes in regional weather, including precipitation changes leading to floods in some areas and droughts in others, hitting some already-stressed areas like Africa harder than others, but obviously overall milder effects than in the higher RCPs.
And that’s kind of the object lesson here. With more realistic and more likely emissions pathways, all these things will be more extreme.
Global warming isn’t a hoax made up by the Chinese. It’s an evil plot by Canadians to finally make their country habitable!
Remember that there’s a difference between global warmth and global warming. Warmth might be good, if (for instance) it allows Canada to grow more food. But the process of transition is difficult. Just what crops, for instance, will grow well in the new Canada? How long will it take to figure out? By the time we do figure it out, will the answer still even be the same?
Hey, wanna retire to a beautiful vineyard in warm (and getting warmer) southern Ontario? Say, in the Niagara Escarpment, Twenty Valley, or Niagara-on-the-Lake? The wine is getting better than ever, the vineyards soaking in the sunshine and warming climate. Here’s the deal. I don’t know how you found out about the Great Canadian Global Warming Project, but just shut up about it, OK? We’re all friends here. Then come on up and move in to your free vineyard. California wine is going to get left behind, don’t miss out!
But the transitions between those extremes were long, hundreds of thousands to millions of years, usually. At any one time in those “wild cycles”, it’s likely that the climate would appear fairly stable to any hypothetical humans living then.
In more recent times, the Earth has gone through about 20 ice ages in the last 2.5 million years. I do not consider that to be a stable period. While humans definitely didn’t cause the ice ages, it’s possible that human activity accelerated the end of the last one.
Some people may be interested in this projection of the change in sources of energy production over the next 30 years: Wind & Solar To Achieve 50% By 2050 As Coal Shrinks To 11%, Predicts BNEF. Unfortunately, while coal-produced energy will shrink, that from natural gas will stay about the same.
Higher [CO2] alone would be a good thing in many situations (not in every situation, but in many). I don’t think it would help corn much since corn already has carbon-concentrating mechanisms, but it would probably help most plants in most situations. The problem is that (barring certain geoengineering mechanisms) higher [CO2] is going to be accompanied by higher temperatures, which are going to generally be bad for photosynthesis and plant growth. The net, combined effect of the two is going to be negative.
Much of the land where Canadians would be “growing more food” is currently occupied by boreal forest or in some cases grasslands, and I don’t really want to see the boreal forest cut down to make space for wheat fields.
The article GIGObuster quoted back in December is incorrect:
Let’s all maybe try to remember back to seventh grade Earth Science lessons on the carbon cycle before posting? Carbon dioxide is removed by reactions with weathering silicate rocks. (It is also added by microbial weathering of other kinds of rock.) Biological uptake can be carbon neutral, but those fossil fuels didn’t get underground by a process that was carbon neutral on any time scale we care about. Limestone? Shale? Meters-deep topsoil? Plants and mollusks dont just go up in smoke when they die.
Indeed, I should have specified northern Central Australia … Nhulunbuy averages a bit over four feet of rainfall per year … some climate change predictions would expand this rain belt to the south some … but not much, turning what is now an arid climate into a semi-arid climate; a semi-arid climate into a moist subtropical climate etc etc etc …
Here’s a graph of global temperatures over the past half billion years … hardly “stable” … also note it’s as cold right now as it ever has been since the dawn of the Cambrian … burrrrrrrr … just looking at that graph makes me want to set coal mines on fire …
I’m at a loss trying to think of a crop that grows well in Minnesota (with adequate rainfall) but doesn’t grow very well in Georgia (with adequate rainfall) … that’s more than a 3ºC average temperature difference …
It gets really fucking HOT in the Imperial Valley, California … we can’t grow anything there not because it’s hot, but because there’s almost no rainfall … build canals to transport Colorado River water there for irrigation and we grow an amazing amount of food there today … and things that won’t grow in Minnesota (very well) …
Corn, wheat, rice … these are annual plants … given 72 generations we can adapt them for the warming world with just Mendelian breeding techniques … a little gene splicing and I think we’re safe … that’s if we choose not to truck Georgia corn varieties up to Minnesota if that’s any help …
We’re basing this assertion on what we learned in first year chemistry … redox reactions … CO[sub]2[/sub] is carbon in its fully oxidized state … we have to add energy to reduce it to one of its reduced states, like CH[sub]4[/sub] … photosynthesis is far and away the most common means for this reduction, and most of this occurs in the world’s oceans … carbonate rock formation directly from CO[sub]2[/sub] is slow so it’s not really anything more than a trivial sink for atmospheric carbon … I believe most limestone is formed from carbon already reduced by photosynthesis …
You certainly didn’t learn* that* in first year chemistry.
I learned that on a concrete slab … some finishers bother to learn about their trade …
Limestone is primarily calcium carbonate. No photochemical reduction required.
Peculiar counter when the cite does show a carbon cycle, and there is a link to NASA that explains the weathering :
https://earthobservatory.nasa.gov/Features/CarbonCycle/
Now, why is weathering not prominently mentioned in the original cite? Because it is not as quick as we humans would appreciate.
Mind you, it is an important component of the eventual sequestration of all the CO2 we are dumping into the atmosphere, but the reason the sequestration of the oceans gets prominence is because is one of the sequestration factors that takes place at a faster rate than weathering. The point here is than then, yes 7th grade Earth science lessons were taken into account. And for people that are interested in more advanced classes the words to look for are: The Slow Carbon Cycle.
What “counter”? You posted factually incorrect information. It has been corrected.
Do you want to still insist that there was no Carbon Cycle in the cite and that there was no link to what NASA reports about it?
What ever are you going on about?