The "bad exponential stuff" that the online doomers seem to cling to is almost always:
1) permafrost melt, albedo feedbacks, etc., which has been considered in the most recent IPCC reports and is still being researched
2) sudden mass extinction due to biodiversity loss
As far as 1) goes, read the IPCC report and get back to me. 2) is scarier, for sure, but there is not enough research done to conclude that we have breached or are about to breach an extinction tipping point. Some recent models suggest phytoplankton extinction (the usual tipping point in doomer arguments) may be reversed in lower latitudes in a warming climate. But no one knows.
“Many of those making facile comparisons between the current situation and past mass extinctions don’t have a clue about the difference in the nature of the data, much less how truly awful the mass extinctions recorded in the marine fossil record actually were,” he wrote me in an email. “It is absolutely critical to recognize that I am NOT claiming that humans haven’t done great damage to marine and terrestrial [ecosystems], nor that many extinctions have not occurred and more will certainly occur in the near future. But I do think that as scientists we have a responsibility to be accurate about such comparisons." https://www.theatlantic.com/science/archive/2017/06/the-ends...
As far as sudden mass extinction, I believe we've already reached the tipping point, but the unraveling processes of ecosystems take decades or even centuries. Big systems crash slow (even in computers! compare a nanosecond-scale hardware fault with a microsecond-scale SIGSEGV with a millisecond-scale NullPointerException with a seconds- or minutes-scale crash of a large web service; that's literally 9 orders of magnitude difference). Earth systems are starting to crash. Look at recent articles about the Great Barrier reef or the loss of kelp forests off the coast of California. These are just the leading edge of things coming apart, the snapping and cracking of support lines starting to come apart. Other things are coming apart at different timescales. Like the forests in Utah and Arizona that dying from higher elevations down due to warming, or being invaded by invasive species. In the midwest where I am, over just a few decades, farmland and forest turned into subdivisions. Raccoons, possum, deer, turtles, frogs, all disappearing. Lightning bugs disappearing. In California again, Monarchs disappearing.
Fire up Google Maps/Earth. Turn off all labels, and just pick a random place on Earth that isn't a desert. Chances are it's farms or turning into farms or suburbs or city. And land use change has accelerated. We've more tractors, backhoes, bulldozers, dumptrucks, roads, and gasoline than ever before. The ability to move dirt, cut down trees, landscape, build--growing exponentially. The Amazon is going, square mile by square mile, never to return. And with it, all the intricate little things alive there. We need meat!
We'll either crash or keep going. If we keep going, most life on this planet is threatened. And we aren't slowing down. We are speeding up. Like growing a watermelon in a lightbulb.
Our entire society is a tech machine that's eating it all. Bye, rabbits.
As I stated elsewhere, I'm not inclined to debate the particulars, but I will note that we've learned a LOT since https://en.wikipedia.org/wiki/IPCC_Fifth_Assessment_Report came out seven years ago. The sixth report, due to come out next year, which will still tend toward extremely conservative conclusions, is going to crush the findings in the previous report in terms of 'bad news'.
As to the other particulars, I've been researching and reading about those and many other categories for literally decades now. That doesn't make me right, and it doesn't make you wrong, but it has led me to realize and embrace the simple truth that even unlimited, good faith energies applied to debate over the details has basically no impact on anybody's opinions.
All that really matters is personal background and personal experiences. And your personal background (including, in large part, your DNA) and personal experiences are different from mine.
Going forward, however, we will share awareness of more and more frequent 100 year/500 year/1000 year weather events, for example.
I have no way of predicting how that will affect your view on things, and that's fine. Full and deep acceptance is a very useful tool.
To cherry pick one item:
> ... as scientists we have a responsibility to be accurate ...
Amen and amen. It's easier than ever to represent real problems in a hyperbolic fashion, but we must not do that. First: because inflated threats and predictions will cause those among us who are slower to accept the realities ahead to entrench, and be even less likely to see what's really happening. Second and most importantly: our best chance to beat this is to, together, focus on being clear, understanding and calm.
