GLOBAL warming isn’t a prediction. It is happening. That is why I was so troubled to read a recent interview with President Obama in Rolling Stone in which he said that Canada would exploit the oil in its vast tar sands reserves “regardless of what we do.”

If Canada proceeds, and we do nothing, it will be game over for the climate.

Canada’s tar sands, deposits of sand saturated with bitumen, contain twice the amount of carbon dioxide emitted by global oil use in our entire history. If we were to fully exploit this new oil source, and continue to burn our conventional oil, gas and coal supplies, concentrations of carbon dioxide in the atmosphere eventually would reach levels higher than in the Pliocene era, more than 2.5 million years ago, when sea level was at least 50 feet higher than it is now. That level of heat-trapping gases would assure that the disintegration of the ice sheets would accelerate out of control. Sea levels would rise and destroy coastal cities. Global temperatures would become intolerable. Twenty to 50 percent of the planet’s species would be driven to extinction. Civilization would be at risk.

That is the long-term outlook. But near-term, things will be bad enough. Over the next several decades, the Western United States and the semi-arid region from North Dakota to Texas will develop semi-permanent drought, with rain, when it does come, occurring in extreme events with heavy flooding. Economic losses would be incalculable. More and more of the Midwest would be a dust bowl. California’s Central Valley could no longer be irrigated. Food prices would rise to unprecedented levels.

If this sounds apocalyptic, it is. This is why we need to reduce emissions dramatically. President Obama has the power not only to deny tar sands oil additional access to Gulf Coast refining, which Canada desires in part for export markets, but also to encourage economic incentives to leave tar sands and other dirty fuels in the ground.

The global warming signal is now louder than the noise of random weather, as I predicted would happen by now in the journal Science in 1981. Extremely hot summers have increased noticeably. We can say with high confidence that the recent heat waves in Texas and Russia, and the one in Europe in 2003, which killed tens of thousands, were not natural events — they were caused by human-induced climate change.

We have known since the 1800s that carbon dioxide traps heat in the atmosphere. The right amount keeps the climate conducive to human life. But add too much, as we are doing now, and temperatures will inevitably rise too high. This is not the result of natural variability, as some argue. The earth is currently in the part of its long-term orbit cycle where temperatures would normally be cooling. But they are rising — and it’s because we are forcing them higher with fossil fuel emissions.

The concentration of carbon dioxide in the atmosphere has risen from 280 parts per million to 393 p.p.m. over the last 150 years. The tar sands contain enough carbon — 240 gigatons — to add 120 p.p.m. Tar shale, a close cousin of tar sands found mainly in the United States, contains at least an additional 300 gigatons of carbon. If we turn to these dirtiest of fuels, instead of finding ways to phase out our addiction to fossil fuels, there is no hope of keeping carbon concentrations below 500 p.p.m. — a level that would, as earth’s history shows, leave our children a climate system that is out of their control.

We need to start reducing emissions significantly, not create new ways to increase them. We should impose a gradually rising carbon fee, collected from fossil fuel companies, then distribute 100 percent of the collections to all Americans on a per-capita basis every month. The government would not get a penny. This market-based approach would stimulate innovation, jobs and economic growth, avoid enlarging government or having it pick winners or losers. Most Americans, except the heaviest energy users, would get more back than they paid in increased prices. Not only that, the reduction in oil use resulting from the carbon price would be nearly six times as great as the oil supply from the proposed pipeline from Canada, rendering the pipeline superfluous, according to economic models driven by a slowly rising carbon price.

But instead of placing a rising fee on carbon emissions to make fossil fuels pay their true costs, leveling the energy playing field, the world’s governments are forcing the public to subsidize fossil fuels with hundreds of billions of dollars per year. This encourages a frantic stampede to extract every fossil fuel through mountaintop removal, longwall mining, hydraulic fracturing, tar sands and tar shale extraction, and deep ocean and Arctic drilling.

President Obama speaks of a “planet in peril,” but he does not provide the leadership needed to change the world’s course. Our leaders must speak candidly to the public — which yearns for open, honest discussion — explaining that our continued technological leadership and economic well-being demand a reasoned change of our energy course. History has shown that the American public can rise to the challenge, but leadership is essential.

The science of the situation is clear — it’s time for the politics to follow. This is a plan that can unify conservatives and liberals, environmentalists and business. Every major national science academy in the world has reported that global warming is real, caused mostly by humans, and requires urgent action. The cost of acting goes far higher the longer we wait — we can’t wait any longer to avoid the worst and be judged immoral by coming generations.

© 2012 New York Times. All rights reserved.

Helena, Mont.

TREES are on the front lines of our changing climate. And when the oldest trees in the world suddenly start dying, it’s time to pay attention.

North America’s ancient alpine bristlecone forests are falling victim to a voracious beetle and an Asian fungus. In Texas, a prolonged drought killed more than five million urban shade trees last year and an additional half-billion trees in parks and forests. In the Amazon, two severe droughts have killed billions more.

The common factor has been hotter, drier weather.

We have underestimated the importance of trees. They are not merely pleasant sources of shade but a potentially major answer to some of our most pressing environmental problems. We take them for granted, but they are a near miracle. In a bit of natural alchemy called photosynthesis, for example, trees turn one of the seemingly most insubstantial things of all — sunlight — into food for insects, wildlife and people, and use it to create shade, beauty and wood for fuel, furniture and homes.

For all of that, the unbroken forest that once covered much of the continent is now shot through with holes.

Humans have cut down the biggest and best trees and left the runts behind. What does that mean for the genetic fitness of our forests? No one knows for sure, for trees and forests are poorly understood on almost all levels. “It’s embarrassing how little we know,” one eminent redwood researcher told me.

What we do know, however, suggests that what trees do is essential though often not obvious. Decades ago, Katsuhiko Matsunaga, a marine chemist at Hokkaido University in Japan, discovered that when tree leaves decompose, they leach acids into the ocean that help fertilize plankton. When plankton thrive, so does the rest of the food chain. In a campaign called Forests Are Lovers of the Sea, fishermen have replanted forests along coasts and rivers to bring back fish and oyster stocks. And they have returned.

Trees are nature’s water filters, capable of cleaning up the most toxic wastes, including explosives, solvents and organic wastes, largely through a dense community of microbes around the tree’s roots that clean water in exchange for nutrients, a process known as phytoremediation. Tree leaves also filter air pollution. A 2008 study by researchers at Columbia University found that more trees in urban neighborhoods correlate with a lower incidence of asthma.

In Japan, researchers have long studied what they call “forest bathing.” A walk in the woods, they say, reduces the level of stress chemicals in the body and increases natural killer cells in the immune system, which fight tumors and viruses. Studies in inner cities show that anxiety, depression and even crime are lower in a landscaped environment.

Trees also release vast clouds of beneficial chemicals. On a large scale, some of these aerosols appear to help regulate the climate; others are anti-bacterial, anti-fungal and anti-viral. We need to learn much more about the role these chemicals play in nature. One of these substances, taxane, from the Pacific yew tree, has become a powerful treatment for breast and other cancers. Aspirin’s active ingredient comes from willows.

Trees are greatly underutilized as an eco-technology. “Working trees” could absorb some of the excess phosphorus and nitrogen that run off farm fields and help heal the dead zone in the Gulf of Mexico. In Africa, millions of acres of parched land have been reclaimed through strategic tree growth.

Trees are also the planet’s heat shield. They keep the concrete and asphalt of cities and suburbs 10 or more degrees cooler and protect our skin from the sun’s harsh UV rays. The Texas Department of Forestry has estimated that the die-off of shade trees will cost Texans hundreds of millions of dollars more for air-conditioning. Trees, of course, sequester carbon, a greenhouse gas that makes the planet warmer. A study by the Carnegie Institution for Science also found that water vapor from forests lowers ambient temperatures.

A big question is, which trees should we be planting? Ten years ago, I met a shade tree farmer named David Milarch, a co-founder of the Champion Tree Project who has been cloning some of the world’s oldest and largest trees to protect their genetics, from California redwoods to the oaks of Ireland. “These are the supertrees, and they have stood the test of time,” he says.

Science doesn’t know if these genes will be important on a warmer planet, but an old proverb seems apt. “When is the best time to plant a tree?” The answer: “Twenty years ago. The second-best time? Today.”

© 2012 New York Times. All rights reserved.

New York Times

In 2011, as in 2010, America was in a technical recovery but continued to suffer from disastrously high unemployment. And through most of 2011, as in 2010, almost all the conversation in Washington was about something else: the allegedly urgent issue of reducing the budget deficit.

This misplaced focus said a lot about our political culture, in particular about how disconnected Congress is from the suffering of ordinary Americans. But it also revealed something else: when people in D.C. talk about deficits and debt, by and large they have no idea what they’re talking about — and the people who talk the most understand the least.

Perhaps most obviously, the economic “experts” on whom much of Congress relies have been repeatedly, utterly wrong about the short-run effects of budget deficits. People who get their economic analysis from the likes of the Heritage Foundation have been waiting ever since President Obama took office for budget deficits to send interest rates soaring. Any day now!

And while they’ve been waiting, those rates have dropped to historical lows. You might think that this would make politicians question their choice of experts — that is, you might think that if you didn’t know anything about our postmodern, fact-free politics.

But Washington isn’t just confused about the short run; it’s also confused about the long run. For while debt can be a problem, the way our politicians and pundits think about debt is all wrong, and exaggerates the problem’s size.

Deficit-worriers portray a future in which we’re impoverished by the need to pay back money we’ve been borrowing. They see America as being like a family that took out too large a mortgage, and will have a hard time making the monthly payments.

This is, however, a really bad analogy in at least two ways.

First, families have to pay back their debt. Governments don’t — all they need to do is ensure that debt grows more slowly than their tax base. The debt from World War II was never repaid; it just became increasingly irrelevant as the U.S. economy grew, and with it the income subject to taxation.

Second — and this is the point almost nobody seems to get — an over-borrowed family owes money to someone else; U.S. debt is, to a large extent, money we owe to ourselves.

This was clearly true of the debt incurred to win World War II. Taxpayers were on the hook for a debt that was significantly bigger, as a percentage of G.D.P., than debt today; but that debt was also owned by taxpayers, such as all the people who bought savings bonds. So the debt didn’t make postwar America poorer. In particular, the debt didn’t prevent the postwar generation from experiencing the biggest rise in incomes and living standards in our nation’s history.

But isn’t this time different? Not as much as you think.

It’s true that foreigners now hold large claims on the United States, including a fair amount of government debt. But every dollar’s worth of foreign claims on America is matched by 89 cents’ worth of U.S. claims on foreigners. And because foreigners tend to put their U.S. investments into safe, low-yield assets, America actually earns more from its assets abroad than it pays to foreign investors. If your image is of a nation that’s already deep in hock to the Chinese, you’ve been misinformed. Nor are we heading rapidly in that direction.

Now, the fact that federal debt isn’t at all like a mortgage on America’s future doesn’t mean that the debt is harmless. Taxes must be levied to pay the interest, and you don’t have to be a right-wing ideologue to concede that taxes impose some cost on the economy, if nothing else by causing a diversion of resources away from productive activities into tax avoidance and evasion. But these costs are a lot less dramatic than the analogy with an overindebted family might suggest.

And that’s why nations with stable, responsible governments — that is, governments that are willing to impose modestly higher taxes when the situation warrants it — have historically been able to live with much higher levels of debt than today’s conventional wisdom would lead you to believe. Britain, in particular, has had debt exceeding 100 percent of G.D.P. for 81 of the last 170 years. When Keynes was writing about the need to spend your way out of a depression, Britain was deeper in debt than any advanced nation today, with the exception of Japan.

Of course, America, with its rabidly antitax conservative movement, may not have a government that is responsible in this sense. But in that case the fault lies not in our debt, but in ourselves.

So yes, debt matters. But right now, other things matter more. We need more, not less, government spending to get us out of our unemployment trap. And the wrongheaded, ill-informed obsession with debt is standing in the way.

© New York Times 2012

Blip32962 here:  I was also favorably impressed -- more so than usual -- by the lead editorial in yesterday's New York Times.  It was headlined "Where the Real Jobs Are" and it seems to me a no-brainer that we should be making the same kind of all-out push toward green energy companies that John F. Kennedy put into place regarding sending manned flights to the Moon.

The Times wrote:

Where the Real Jobs Are