This article [1] in the journal Limnology and Oceanography (and others) indicates to me that we don't understand the effect of climate change on methane emissions from the Arctic and Antarctic seabed. Are emissions going up or down?
Wildfires in the western US are increasing, but we've changed the way we manage forests and forest fires in the west. The resulting accumulation of brush in forests (for one reason because we aggressively put out even small fires to protect encroaching development) makes big fires more likely. Furthermore on the scale of centuries, as long as the forests stand they will simply recycle CO2 by absorbing it as trees grow and by releasing it when they die (either through rotting and decay or by burning).
As far as the oceans not acting as CO2, the recent literature that I've read says that they are acting as CO2 sinks. The first two sentences of the abstract from a Feb. 2017 paper in Nature[2] are:
"The ocean is the largest sink for anthropogenic carbon dioxide (CO2), having absorbed roughly 40 per cent of CO2 emissions since the beginning of the industrial era. Recent data show that oceanic CO2 uptake rates have been growing over the past decade reversing a trend of stagnant or declining carbon uptake during the 1990s"
[1] Limnology and Oceanography. Effects of climate change on methane emissions from seafloor sediments in the Arctic Ocean: A review, http://onlinelibrary.wiley.com/doi/10.1002/lno.10307/full
[2] Nature. Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning. https://www.nature.com/nature/journal/v542/n7640/abs/nature2...
In particular, there are multiple attractor states where the planet's temperature can maintain an approximate equilibrium for long periods of time -- one of these is just below our current mean temperature, and the next one up is thought to be about 10 degrees Celsius warmer, closer to the temperature experienced during the Paleocene-Eocene thermal maximum. Then of course there are ice ages, which, if aided by low CO2 levels, can result in the extreme low temperature of a "Snowball Earth."
We are likely out of the equilibrium of our interglacial and in the beginning stages of a positive feedback loop that will continue increasing the planet's temperature until most of Earth's ice is melted and deserts expand in the low-mid latitudes, at which point blackbody radiation will offset the decreased albedo from lower ice levels.
There are more complex, unpredictable dynamics at play as well that may serve as negative feedback. For example, less Arctic sea ice is predicted to result in more snow in the far north due to increased evaporation, which may serve to build up glaciers on land.
Another factor is climate lag, also called climate inertia. There is a delay of a couple of decades between emissions and temperature change. The thing is we have emitted more in the past decades than the previous 150 years before that.
So even if a miracle happened and we got to zero emissions there are still self sustaining feedbacks and a monstrous wave of warming coming at us.
Our only hope really are extreme negative emissions, but I feel we won't even be able to make it to zero emissions.
See also https://www.eenews.net/stories/1060057298, posted to HN a week ago: https://news.ycombinator.com/item?id=14764043
As Antarctic glaciers flow out toward the ocean, they form shelves over the water. At ape point, the shelf becomes too large to sustain itself and collapses. This is what happened recently, and it's an event that would have happened no matter what.
> Dr Martin O’Leary: “Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history."
I interpret those comments as saying it's currently an open research question. Lots of popular press I've read though does leap to there being some link. I think it pays to be open minded here and consider that ocean and polar warming could have an impact on ice shelf stability.
I'm curious; in the context of the ice front, when does recorded history begin?
Are we talking, 10s, 100s, or 1000s of years?
https://www.nasa.gov/topics/earth/features/warming_antarctic...
There is still the whole "correlation isnt causation / aint necessarily so" caveat, but the correlation with AWG is obvious.
It will still prevent exacerbating the problem.
We still have an opportunity to reduce the extent of the damage. Major climate change is likely inevitable at this point as, realistically, the modest measures taken to date are insufficiently binding to be effective.
I don't think we've past the point of no return, yet, but we will certainly do so at some point given the real cost of taking action appears to grow faster than the political will to take action.
I'm not saying we shouldn't try, but I fear we're already past the point of no return for catastrophic climate change.