My biggest fear today is that we're already screwed and just don't know it. This article turned out to be a "We expected this and now we've found it" but every morning I worry I'll see a headline like this and it'll be "We turned over this one rock and found something we didn't expect. Prepare for global famine in 2 years."

On our current course I'm quite optimistic that we'll be able to turn the ship around - I think between tech accelerating and the climate itself starting to put the screws on us, we'll have powerful enough tools and enough resources poured into them to save ourselves. However, that's if we stay on the apparent current course. I'm really scared we'll hit a discontinuity of some sort.

We know it.

Release of CO2 has entered a positive feedback loop. Thawing tundra, burning forests, ocean acidification.

Even this we could counter (painfully) with massive industrial scale sequestration.

What worries me is methane. I'm not sure we can mitigate methane released from the tundra. And if the stuff tucked under the ocean pops, we're toast.

https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

What I don't get about the positive feedback loop argument is that it seems completely at odds with what the IPCC is saying, namely limiting emissions in order to stabilize global warming at 2 degrees.

If we were in a positive feedback loop, then global warming will just continue to accelerate no matter how small our emissions are. In fact, we'd be equally screwed if we magically stopped emitting CO2 in 1950, it would just take a little bit longer before we're screwed.

Can anyone explain how to reconcile these arguments?

Methane doesn't stay in the atmosphere nearly as long which means that, in theory, it would cause some short term warming, but then the methane would break down and we would slowly return to more normal levels. There are alot of unknowns, and while a very worst case scenario involves runaway methane causing warming, we don't know how likely this is to happen. We do know that CO2 takes hundreds of years to dissipate and will cause the ice caps to melt which will lead to higher sea levels overall.

IPCC does consider tundra, methane, feedback loops.

https://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch4s4-4...

Citations elided:

"Arctic and sub-Arctic ecosystems (particularly ombrotrophic bog communities, see Glossary) above permafrost were considered likely to be most vulnerable to climatic changes, since impacts may turn Arctic regions from a net carbon sink to a net source. Literature since the TAR suggests that changes in albedo and an increased release of methane from carbon stocks, whose magnitudes were previously substantially underestimated, will lead to positive radiative climate forcing throughout the Arctic region."

In my opinion, even the worst possible effects of climate change (flooding, storms, acidification, desertification, species die-off, restoration of crocodiles living on Greenland)...

will not be enough of a problem for the most-polluting humans to care about

> will not be enough of a problem for the most-polluting humans to care about

I live in the country that pollutes the most per capita. I'm ashamed to say I haven't significantly changed my behavior and consumption patterns. But I look around myself and nobody else has either. Heck, we even voted in someone whose team wants to take actions that accelerate climate change. So this party will keep going until something terrible happens that actually impacts the folks at the top.

They will move to New Zealand or make Hail Mary effort to colonize off-planet, and then war and famine pick off the 5-6 billion people that the earth cannot sustain (absent massive changes). Some of the people at the top know about this (in the country you are referencing), and they don't care. This is why they are attempting to systematically take apart health care, education, means of disseminating information, and other pillars of a resilient civic society.

>I haven't significantly changed my behavior and consumption patterns

You shouldn't be ashamed about this per se, because the type of action that will combat climate change is action by governments and corporations. An Inconvenient Truth made everyone think that small personal decisions are the way toward a greener future (think changing your lightbulb), but they aren't.

No, small personal decisions are the way forward. As that accumulates opinion which then changes which party and policies people vote for, their buying patterns, etc and therefore changes government/corporations.

Will it though? That's what worries me about climate change. I think the whole situation is subject to Jevons Paradox:

https://en.wikipedia.org/wiki/Jevons_paradox

Using less CO2 (for a given activity) without reducing well being much just means we are becoming more efficient with it. Which means we could potentially use more CO2, globally.

Don't get me wrong, I think individual action is good. But will it solve it? I think the only things that would solve it are:

1. Making a source of energy superior enough to CO2 that people don't even desire carbon 2. Leaving the carbon in the ground

I think #1 may be a precondition for #2.

Of course, if the small personal decisions help develop the technology in #1, they may help more directly than simply reducing consumption.

I believe you're right about individual decisions to become more active on these issues can make a difference both on the government and the business level. In many ways, it already has made a difference as many businesses, even in the most cautious industries, have tried to at least do something to reduce their emissions.

However, the impacts of an individual, even collectively, don't matter much on this issue. The change has to come in the way energy is generated in the large scale if it's going to make a difference in the problem. It also takes actions from government like a carbon tax or incentives to create more clean energy sources, or both to push these collective decisions in a better direction.

This position though is pretty much contingent on nearly every person making nearly every environmentally-friendly decision then, no?

How do you think people decide which small personal decisions to make?

I don't blame you :) it is a crisis of leadership for sure, since so many rich businesses are polluting, and so many individual consumers justify things to themselves by saying "but i NEED my SUV, mcmansion, refrigerator" and etc

in my opinion it will be more necessary to find a way to suck co2 out of the atmosphere and place it somewhere, rather than attempt to limit how much demand there is for things that produce it as a waste product

"find a way to suck co2 out of the atmosphere and place it somewhere"

That's what forests do, and we're cutting them down with alacrity.

Also, I don't think you're done the "number of humans" x "energy consumption of suv + mcmansion" + "carbon density of likely fuel sources" math yet. It is simply impossible to sustain.

More trees and plant cover can help in the short term, but it's not going to solve the long term problem because those trees will break down and release the CO2 they've captured. This wasn't always the case as the ability for microbes and fungi to break down trees evolved later, which is how many of those coal deposits were created in the first place.

The main benefits from forest are habitats for wildlife, prevention of erosion, and ways to improve biodiversity. Their benefits to climate change are limited to reduced sunlight absorption because of their higher reflectivity and a small amount of a carbon sink if they take over land that was cleared and turned into plains, or farms or whatever.

Yup, fully aware of the Carboniferous period. But in a world with fungi, the CO2 is still trapped as the living trees and as trees die they are replaced with new ones. There is a steady state equilibrium.

I am not pro SUV or pro mcmansion

i am pro forest

Me too! Wasn't implying otherwise :)

Sweet!! It is a funny situation, isn't it? We have a natural organism that does quite literally suck CO2 out of the air and replace it with O2, which we just so happen need to breathe.

and yet many actors from many different societal origins are chopping down trees for furniture, building, fuel, etc etc. If the answer is as simple as "hire a bunch of people to plant trees", then it makes one wonder why money hasn't been diverted for this either at a governmental or charity level

Seems promising: Meet the Scientist Turning CO2 Into Ethanol - http://www.popularmechanics.com/science/green-tech/interview...

It is just a battery, and not a very good one. The energy efficiency is only 20% - meaning you have to use 4 times the energy to run the reaction and convert the CO2 as you will get from burning the ethanol. And of course burning the ethanol releases the CO2. If you want to sequestor carbon I don't think this is a promising route to take.

Great, thank you! this would help put a dent in climate change AND land use complaints surrounding ethanol :)

We already have this technology, they're known as CO2 scrubbers.

I have a bad memory but I seem to recall Sergey Bring or Larry Wall or someone "important in technology" saying that this is basically already a solved problem -- heavily investing in to CO2 scrubber technology, hooking the things up via solar, and deploying them across the world's deserts -- but that todays problem is that leadership problem you mentioned. No one (Government) wants to foot the bill.

Qatar?

What makes you think that people will change when the worst effects will begin?

I don't know if I'm a pessimist or a realist.

Are your views consistent with the sum total of human behavioral history? If so, I'd say you're not being pessimistic at all.