[glenra]

> Most researchers say that actually IPCC is rather conservative in its views not the other way around.

Sure, if you're listening to people like David Suzuki you'd have that impression. But on the other side there are people like Chris Landsea - here was his resignation letter from the IPCC:

http://cstpr.colorado.edu/prometheus/archives/science_policy...

The IPCC's charter is to tell us about risks related to climate change. Not the benefits. If there weren't any risks or we were fully informed about them, the IPCC would have no institutional reason to continue to exist. So naturally it focuses on the latest big scary "we just noticed THIS risk!" stories and puts much less emphasis on "it turns out we were wrong about THAT risk!" stories. For all we know, each new report could be exactly the same as the last one in terms of the net overall danger documented and it would still look like things were "getting worse", because areas where things are "getting better" generally aren't mentioned or are soft-pedaled.

For instance, the IPCC once tried to claim a high certainty that there'd be more hurricanes in the future due to climate change (see Landsea's letter linked above), but now they either don't make such claims or assign them a much lower certainty level. The IPCC once claimed Himalayan glaciers would be gone by 2035 ( http://www.theguardian.com/environment/2010/jan/20/ipcc-hima... ); that turned out to be a mistaken claim based on grey literature. If there were some sort of a rundown in each report listing all the ways things "are worse" AND all the ways things "are better" since the last one it'd be easy to keep score. But there isn't, and the summaries and press releases emphasize any mentioned "this is worse" stories because bad news travels fast.

Suzuki complains that the IPCC report doesn't focus on the loss of arctic sea ice, but if they DID mention sea ice, they might have to mention that overall sea ice levels worldwide are currently above the long-term (30 year) average because we've gained more sea ice cover in the antarctic than we've lost in the arctic. And so on. (Given a big, complicated planet you can always find SOME areas or trends that seem to be "getting worse" but that doesn't mean throwing them - and only them - into the mix would make the report more accurate.)

[couchnaut]

That's a highly political (i.e. lots of beating around the bush) resignation letter. What's his point exactly? That IPCC has vested interests in fear mongering or what? And what exactly are the good things that we can expect from climate change? In any case I believe that just the accelerating rate of catastrophic weather incidents is dismantling that argument(?). Of course there is a multitude of interests and even a market for climate change (i.e. books about it) but this doesn't mean that the problem is not there, evolving and getting worse every day. He -too- does not deny that.

About the Arctic/Antarctic ice: I guess that http://www.skepticalscience.com/argument.php argument 25 addresses that. Also seeing the whole system oscillating between extremes (too few ice - more ice) is not comforting or reassuring that it reaches a new balance.

PS: I'm not Suzuki's spokesperson. I didn't even know the guy till yesterday. Maybe he's overeacting and maybe not. I also note that the party is obviously full of fear mongers and shady traders of all sorts. I also note that it is not logical to dismiss the whole argument because of such people.

PS2: HN is the last place I would expect to find myself fighting against climate change skeptics.

[glenra]

Landsea's point is that the IPCC was making alarmist official statements that had no basis in fact and ran counter to the underlying scientific literature. Landsea was the relevant expert on the subject and even he couldn't stop the fear-mongering; he quit because he didn't want to be associated with it. The issue he quit over was that there really wasn't an "accelerating rate of catastrophic weather incidents" to the degree the IPCC was trying to claim at the time.

On good things we can expect: The main measurable good thing we can expect from the next 1-3 degrees of warming is increased agricultural productivity. In the northern areas where most of the world's food is grown, warmer average temperatures means a longer growing season which makes it easier to feed the world. (It also increases the range where we can grow crops and makes winters less bitterly cold in places like Canada.) Closer to the equator the warming part doesn't help so much but the extra CO2 makes forestry more productive - it helps trees grow better due to CO2 fertilization. (My main source on this is the AR4 IPCC report - I haven't read AR5 yet.)

Also: many more humans die each year from excessive cold than from excessive heat; a planet with less bitterly cold winters is a more habitable one.

Also: being warmer puts us a little further away from the next ice age. Climate always changes; given the choice, I'd rather it get a little warmer than a little colder. (There is no reason to think the temperature in, say, 1990 was optimum for human life worldwide. We don't need to return to that, nor do we need to keep it where it is now.)

With regard just to sea ice it's not "oscillating between extremes" so much as there's been a shift over time as to where more sea ice collects on the planet - more in the south, less in the north. Changing sea currents and weather patterns can do that over long cycles. When alarmists look at growing sea ice in the south they dismiss it with "oh, the currents have changed" or "oh, the weather patterns have changed" or "yeah, but ignore that and look at the LAND instead!" but when they look at shrinking sea ice in the north they tend to insist it's due to warming and only that; I'd like to see a little more consistency.

SkepticalScience is not a reliable source - it's a propagandistic site run by a cartoonist, not a scientist - but in this case that's not a factor: argument 25 at that link is about sea level rise. Since I agree that sea levels have (very slowly) been rising over time, I'm not sure how that's relevant. (FWIW, I also agree that measured temperatures increased in the last half of the last century and that CO2 is a greenhouse gas and that some recent warming has been the result of human activity.)

> HN is the last place I would expect to find myself fighting against climate change skeptics

The article you wrote suggested in passing that the planet could become uninhabitable in mere decades because we've passed a bunch of "tipping points" - you're bound to get some pushback if you try to make wild-eyed claims of that sort. If you want to say stuff like that you should try to figure out where the claims are coming from, whether there's any science behind them, and whether the science is any good.

[couchnaut]

So -according to Landsea- IPCC (an international scientific organization) is moving in ways that are more political than scientific. Weird and disturbing. Weird because I'd expect such an organization to be gravitating towards big industrial nations' interests if we're to assume that they are susceptible to lobbying - not the other way around. Disturbing because if they are doing politics rather than science then we have a different kind of problem which is that the bodies of experts that we should be trusting on very complex subjects are not to be trusted and I don't know where that leaves us as a society.

I'll accept the point of not putting forward very well researched links but to my defence: 1. Climatology is far from my expertise. As is microbiology, or nuclear power or space exploration. And that's why I'm ok with paying people (from my taxes) to have an educated opinion on such matters. 2. as you probably know it's quite difficult to find who are the generally respectful scientists (remember dismissing a whole lot of them just a while ago (IPCC)). 3. I -sorry about that- thought that we're past scepticism on the subject as I have only seen that attitude only in conspiracy theorists (right or left leaning). 4. I pitted the problem as a problem that can (or at least should) be solved in the same way that humans have been improving their lives - with ingenuity and a mind for the society as a whole.

Anyway - thank you for your long and researched answer and I sincerely hope that Landsea is right because I don't believe that we're about to change anything in our ways any time soon.

[glenra]

The IPCC is supposed to summarize the state of the existing literature, but it was born political, tends to attracts eco-activists of all sorts and relies more than it should on "grey literature" - unrefereed "reports" written by ecological organizations. The IPCC also to some degree generates the consensus it is supposed to be merely reporting on, in that the lead authors have been known to push specific articles into print supporting "their side" of things and delay articles supporting "the other side" with IPCC deadlines in mind so that their side gets the last word. That's one part of the process where excess alarmism gets to creep in. On the other side, your sources are correct that the result then gets massaged into acceptability. The "summary for policymakers" in particular is the result of political compromises - various country's representatives argue about it and then the rest of the document in some cases gets rewritten to reflect what the summary says, leaving nobody happy.

Nonetheless, the IPCC documents aren't terrible and do tend to be worth reading if you really want to know what's going on.

On being "past skepticism": The most credible skeptics tend to be "lukewarmers". They believe reality is a bit more complicated and uncertain than has been portrayed, they tend to suspect climate sensitivity is a lot lower than the models predict and they tend to be suspicious of doomsday claims generally. But almost nobody at this point doubts "CO2 is a greenhouse gas" or that the planet has warmed, so all those "97% agree!" articles miss the point - the skeptics "agree" too.

A couple good blogs for credible "skeptical" views are: http://judithcurry.com/ http://climateaudit.org/

And a good blog for credible "alarmist" views is: http://www.realclimate.org/

(the most popular source for skeptical views is probably http://wattsupwiththat.com and the most popular source for alarmist views is probably skepticalscience. Those sites are indeed more readable and approachable, but the extra readability in both cases comes at the cost of (1) oversimplification of main posts, (2) attracting much dumber comments. So browse those sort of site with care and don't believe what you read there without checking it. )