Why not require all new construction, both commercial and residential, to make use of passive heating and cooling techniques, and to recycle gray water? Why not demand that any major new building development must achieve LEED Platinum certification?

Why not aim for a total conversion of all new vehicles to be electric by 2020?

Why not begin now? After all, we know with a high degree of certainty that taking all these positive steps would bring many benefits. By weaning ourselves off of fossil fuels, for example, we could move away from the need to maintain unstable and unsavory relationships with dictatorial regimes. It's obvious that nations who depend less on outside sources for non-renewable resources are both more secure and financially stronger.

And beyond the political and economic benefits, there would be significant healthcare benefits. Reducing or eliminating particulates in the atmosphere from burning oil and coal would be revolutionary. Right away, we'd prevent as many as a million deaths a year that are directly attributable to air pollution from fossil fuels. And imagine how clean the skies would look!

Once they learn about what's possible and why we should begin now, for many people this seems like a no-brainer. Of course we should. Why not do it all?

Why not? The most obvious reason is politics -- and behind that is lobbying, and behind that is money, and behind that is power. Those in power today do not want to see all these measures adopted because they fear it would lessen their power.

Another reason is uncertainty. Yes, some of these proposed changes would cost a little more initially than just doing business as usual. And it's not yet clear how fast energy costs will rise or how quickly global warming will accelerate and produce more extreme climate changes. Also, it's possible that if we waited a decade or two, new discoveries or new technologies might arise that would make the job much easier and make the above proposals seem less urgent.

So, we simply can't be sure today whether making these adjustments would pay off in 10 years, in 20 years, or at all. It's also not certain that even if every one of these steps were taken, it would be enough to keep greenhouse gas emissions in check, retard the pace of global temperature increases, and keep the sea from flooding low-lying lands.

Even as drastic as these measures might seem to some, they may not be enough. We, the human race, may still feel compelled to undertake potentially dangerous and hugely expensive geoengineering projects to block sunlight or change the chemistry of the oceans. Or, failing that, we might still be forced to adjust to a new kind of planet, a new Earth with crazy weather, remapped shorelines, and reconfigured growing zones. We might have to watch, no matter what else we do, as millions of our brothers and sisters die of starvation, disease, or poisoned water.



The measures I've sketched out might not be enough. But then again, they might. Or they may combine to make a bad outcome not quite so bad. At the very least, they would be a start.

And then our children and grandchildren would not have to ask us: Why didn't you?