Friday, April 07, 2006

Global warming - another topic to avoid with in-laws...

Thanks perhaps to a shift in media coverage, as well as media consensus, the Great Global Warming Debate has been re-energized. Interesting to note is that the debate now is less scientist vs.scientist and more economist/politician vs. scientist.

Like many, I have poised on the brink of an opinion for a long time. My feeling was this was an argument that could wait. Lately however, I have found myself reluctantly agreeing with the overwhelming majority of the scientific community, as explained lucidly here.

Another good source for new entrants into this fray is here (I found it to be even-handed and well-documented):

Her review of all 928 peer-reviewed papers on climate change published between 1993 and 2003 showed the consensus to be real and near universal. Even skeptical scientists now accept that we can expect some warming. They differ from the rest only in that they believe most climate models overestimate the positive feedback and underestimate the negative, and they predict that warming will be at the bottom end of the IPCC's scale

If the skeptics are to be believed, the evidence for global warming is full of holes and the field is riven with argument and uncertainty. The apparent scientific consensus over global warming only exists, they say, because it is enforced by a scientific establishment riding the gravy train, aided and abetted by governments keen to play the politics of fear. It's easy to dismiss such claims as politically motivated and with no basis in fact - especially as the majority of sceptics are economists, business people or politicians, not scientists (see "Meet the sceptics"). But there are nagging doubts. Could the sceptics be onto something? Are we, after all, being taken for a ride?

I think much of my reluctance was the risk of being categorized as a tree-hugging eco-freak in an industry that claims deep environmental commitment (We were the first environmentalists!) but is strangely averse to cooperating others who seem to have similar goals. Global warming skeptics have become increasing strident and ad hominem attacks are now routine (never a pleasant anticipation either).

Mostly I think we just want to farm as we please until forced by economics to reconsider.

Complicating the debate has been the recent discovery of global dimming:

Global dimming? Does that have something to do with decreasing IQ scores and the proliferation of reality TV? Not quite, but if you missed the story, you would not be the only one. Until Ohmura poked his nose into the radiation record, nobody had noticed that between 1958 and 1988, a whopping 10 percent of solar radiation had disappeared.

At first, I thought, hey, this is good news - it will offset the warming. But, I thought too soon, as usual:

Lohmann explains that clouds change as we emit more particles into the atmosphere. Clouds are made of cloud droplets, which form by latching onto tiny particles called condensation nuclei. These occur naturally in the atmosphere, but by emitting more particulate pollution into the atmosphere, humans help make even more condensation nuclei. The result: Instead of fewer, larger water droplets forming, many, smaller water droplets form. In effect, this is like the difference between two sieves, one coarse and the other fine. Like a coarse sieve, the cloud with fewer, larger particles lets more solar radiation through to the ground, whereas like the fine sieve, the cloud with lots of very small particles lets less sunlight pass through. The result is darker days.

[Rest of helpful article here]
For me the tipping point was the NOAA scientist whose views were "muzzled" by the administration, and the information that flooded out after that fracas. Regardless, I now believe that human action is causing climate change.

OK, I said it. But it may be more than just another policy argument for agriculture. If warming is occurring rapidly (from a climate perspective) it will change the way I farm this year and every succeeding year.

For example, I may need to push slightly longer in maturities or factor in earlier harvests. If storms will pack extra punch due to heating extremes and altered moisture habits, standability will move up as a priority

Ditto for rootworm control. For that matter,
milder winters may mean a whole host of new over-wintering pests.

I'll let the skeptics bet their crops on Michael Crichton's global warming conspiracy theory. It costs me little to respond logically, and could save me some lessons learned the hard way.

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