Text 11604, 87 rader
Skriven 2007-02-05 16:38:57 av Shabaz (15043.babylon5)
  Kommentar till text 11568 av rec.arts.sf.tv.babylon5.moderated (15007.babylon5)
Ärende: Re: Global warming, among other things
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Please, please, please people, take the trouble to read through the
IPCC SPM I linked. And maybe some of their other reports, if you have
time. So we at least have a base line from actual science that you can
talk from. Instead of just making arguments based on "facts" without
sources, in areas that are actually clearly addressed in the actual
science. They're not super readable prose, but it still should be
understandable for most of us, I think.

On Feb 5, 3:55 pm, Methuselah Jones <methuse...@altgeek.org> wrote:
> I'd say we understand enough to say that we potentially have a serious
> problem.

Not potentially. We know global warming is happening. We know with 95%
certainty that there will be even larger climate changes in the 21st
century than in the 20th century at current or higher emission rates.
We know that frequency and intensity of certain extreme weather events
will likely to very likely increase. See the IPCC AR4 SPM. And again,
there is a danger here, which is not change in itself, but large and
rapid change. The larger and more rapid the changes the harder it
becomes to adapt, and the more the negative effects start to dominate.
To quote from the IPCC TAR Synthesis Report SPM:

>>Projected climate change will have beneficial and adverse effects on both
environmental and socio-economic systems, but the larger the changes and rate
of change in climate, the more the adverse effects predominate.<<

>When we can't consistently predict whether it's going to rain
> tomorrow, I don't know how we can say anything with any certainty about
> the next decade or the next century.

Weather prediction and climate change prediction are two fundamentally
different things. While it may seem counter intuitive, predictions in
the larger context of climate can actually be accurate, even if it
still is hard to predict next week's weather. That you have trouble
understanding how this is doesn't make it any less so, and at this
point the certainty levels are fairly high. Again, just read through
the IPCC AR4 SPM: http://www.ipcc.ch/SPM2feb07.pdf

You also may find the write up on this topic at RealClimate.org an
illuminating read: http://tinyurl.com/oet3t

>Yes, the climate is warming[1]. Yes,
> curbing greenhouse gasses is a good idea. Alarmism, however, is not.
> Whatever's going to happen is going to happen.

Emission cuts can have a significant impact. To quote again from the
IPCC TAR Synthesis Report SPM, from the answers to Q6:

>>The greater the reductions in emissions and the earlier they are introduced,
the smaller and slower the projected warming and the rise in sea levels. Future
climate change is determined by historic, current, and future emissions.
Differences in projected temperature changes between scenarios that include
greenhouse gas emission reductions and those that do not tend to be small for
the first few decades but grow with time if the reductions are sustained.<<

We can lower the projected global mean temperature rise by several
full degrees by 2100, making a huge difference. See the full Q6
answers, which you might find interesting. http://www.ipcc.ch/pub/un/
syreng/spm.pdf

> Humans do make an impact
> on the environment, obviously, but I think the overall impact on the
> macrocosm is less significant than many think it is.

Since those "many" includes the opinion that can be derived from the
peer reviewed science out there, you're plain wrong here. The warming
trend *can not* be explained with any confidence without anthropogenic
green house gasses, and anyone who tells you it can is either
misunderstanding the current scientific understanding, or wilfully
misrepresenting it. And to again quote the AR4 SPM: "Most of the
observed increase in globally averaged temperatures since the mid-20th
century is very likely [< 90%] due to the observed increase in
anthropogenic greenhouse gas concentrations."

> As Ray Bradbury
> said, "The human race likes to give itself airs. One good volcano can
> produce more greenhouse gases in a year than the human race has in its
> entire history."

That's a pretty impressive factoid... but I'm pretty sure it is wrong.
With CO2 for instance, volcanoes on average release about 0.15 Gt/year
of carbon into the atmosphere, compared to about 7 Gt/year of human
related sources. They're negligible to what we're doing. For some more
fun reading on this, I'll recommend another RealClimate.org article
(from which I got these numbers): http://tinyurl.com/3483wu
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