Why is it not possible to prove AGW without using words like 'consensus'?

Question

I mean if you wanted to demonstrate the world is round, you woudn't take a vote, you would talk about how you only see the tops of mountains over the horizon or that the sun and stars are in a different part of the sky depending on lattitude.

Also if you wanted to demonstrate the speed of light, you would point to the experiments (the first experimental evidence was that the moons of Jupiter appear to slow down when the earth is moving away from them) rather than how many people believe in it.

Why is AGW different to other scientific concepts in this respect.

Answer 1

Because the empirical proof would mean experiencing demonstrated global warming over years... it would then be too late.

Theory: if you put your fingers in the plug, you will be electrocuted... but it is still only a theory until you make it come true... ready to do it?

Answer 2

Because nothing in science is ever "proven" in the mathematical sense. All of science is subject to revision as new data comes in.

And yes, that includes the speed of light: the original Romer/Huygens measurement was 220000 kps. They were wrong.

It includes the shape of the Earth too, which is not spherical. There are still flat-earthers around. They have a theory. It's a pretty lame theory, but it's there. And there are still "scientific creationists" hanging around too.

And yes, there are those who deny global warming. A few (a very, very few) of those are scientists, mostly older scientists who are defending careers strewn with long-forgotten papers containing views that are now considered laughable or ridiculous by their colleagues. Science is not without its careerists. That's why it takes about two generations to move from consensus to unanimity in science: it takes that long for the old guys to die off. But when the stakes are high, like they are now, we can't wait two generations. We need to act now.

If you don't know the science yourself, it's up to YOU to educate yourself. Don't take my word. Don't take Al Gore's word. And for God's sake, don't take Rush Limbaugh's word. Start here:

http://www.ipcc.ch/ipccreports/ar4-wg1.h...

If you don't understand something, go to the footnotes and look up the references. If you don't understand the references, go to THEIR footnotes and look up THEIR references.

When you get through the whole thing, here are some of the things you might have learned:

1. World surface temperatures are getting warmer, and this trend has accelerated since the mid 1970's. Almost no scientist in the 21st century has disputed this basic fact, even among the most diehard GW skeptics. Here is the data from NASA / GISS:

http://data.giss.nasa.gov/gistemp/tabled...

... and from the UK's Hadley Centre:

http://hadobs.metoffice.com/hadcrut3/

As I said, even GW skeptics accept that it's getting warmer; the major dispute is what's causing it: human beings, through increased greenhouse gases in the air? Or natural causes, like the Sun? The dispute is more political than scientific, though, because the scientific case for increased greenhouse effect is rock solid.

2. If the Sun is causing the current warmth, then we're getting more energy, and the whole atmosphere should be getting warmer. If it's greenhouse, then we're getting the same amount of energy, but it's being distributed differently: more heat is trapped at the surface, and less heat is escaping to the stratosphere. So if it's the Sun, the stratosphere should be warming, but if it's greenhouse, the stratosphere should be cooling.

In fact, the stratosphere has been on a long-term cooling trend ever since we've been keeping radiosonde balloon records in the 1950's. Here's the data:

http://hadobs.metoffice.com/hadat/images...

http://hadobs.metoffice.com/hadat/hadat2...

http://cdiac.ornl.gov/trends/temp/sterin...

3. If it's the Sun, we're getting more energy during the day, and daytime temperatures should be rising fastest. But if it's greenhouse, we're losing less heat at night, and nighttime temperatures should be rising fastest. So if it's the sun, the difference between day and night temperatures should be increasing, but if it's greenhouse, the day-night difference should be decreasing.

In fact, the daily temperature range has been decreasing throughout the 20th century. Here's the science:

http://ams.allenpress.com/perlserv/?requ...

http://ams.allenpress.com/perlserv/?requ...

http://www.bom.gov.au/bmrc/clfor/cfstaff...

4. Total solar irradiance has been measured by satellite since 1978, and during that time it has shown the normal 11-year cycle, but no long-term trend. Here's the data:

http://www.ngdc.noaa.gov/stp/SOLAR/solar...

5. Scientists have looked closely at the solar hypothesis and have strongly refuted it. Here's the peer-reviewed science:

http://www.pubs.royalsoc.ac.uk/media/pro...

http://www.mpa-garching.mpg.de/mpa/publi...

6. CO2 levels in the air were stable for 10,000 years prior to the industrial revolution, at about 280 parts per million by volume (ppmv). Since 1800, CO2 levels have risen 38%, to 385 ppmv, with no end in sight. Here's the modern data...

http://www.esrl.noaa.gov/gmd/ccgg/trends...

... and the ice core data ...

http://www.ncdc.noaa.gov/paleo/icecore/a...

http://www.ncdc.noaa.gov/paleo/icecore/a...

http://www.ncdc.noaa.gov/paleo/icecore/a...

... and a graph showing how it fits together:

http://www.columbusnavigation.com/co2.ht...

7. We know that the excess CO2 in the air is caused by burning of fossil fuels, for two reasons. First, because the sharp rise in atmospheric CO2 started exactly when humans began burning coal in large quantities (see the graph linked above); and second, because when we do isotopic analysis of the CO2 we find increasing amounts of "old" carbon combined with "young" oxygen. Here are the peer-reviewed papers:

http://adsabs.harvard.edu/abs/1984JGR......

http://www.ingentaconnect.com/content/mk...

http://www.sciencemag.org/cgi/content/ab...

So what's left to prove?