The World in 2050: Four Forces Shaping Civilization's Northern Future

Croplands will return to desert. The first signs of an urban takeover have already begun: After years of lawsuits, farmers of California’s Imperial Valley were forced to sell two hundred thousand acre-feet of their yearly Colorado River water allocation to San Diego in 2003. That fallowed twenty thousand acres of farmland. By early 2009 the Metropolitan Water District—supplier of twenty-six cities throughout Southern California—was trying to buy seven hundred thousand acre-feet more.²⁷²

Cities versus farmers: the real Water Wars.

Part Two THE PULL

CHAPTER 5 Two Weddings and a Computer Model

My adoptive groomsman, whom I’d just met the night before, cracked open the church door and peeked anxiously out at the parking lot. It was a sorry mess of black asphalt, lingering slush, and streaming water. Some early guests were sitting in their cars, peering through their headlights for a dry way into the church. It was early afternoon but very dark. I’d expected dim—we were, after all, just three hundred miles shy of the Arctic Circle in the middle of winter—but not this. The expected reflective blanket of fluffy white snow was gone. My dress socks were wet and cold. We’d strategically timed our wedding day for the prettiest, whitest, most winter-wonderland month of the year. But instead, in the middle of February, some five hours north of Helsinki, a thousand miles northeast of London, and almost twenty degrees of latitude north of Toronto—there was only a steady downpour of rain.

More precisely it was our first wedding day, taking place across the Atlantic for my new European family and friends. Our second wedding day—for American families and friends—was a month later in the sunny desert resort of Palm Springs, California. Mid-March is peak tourist season in Palm Springs, with infallible blue skies and flawless temperatures hovering in the 70s. We had booked all outdoor venues for the day’s events. Our tremulous queries about tents and patio heaters—just in case of a weird-weather repeat—were politely but firmly dismissed. The weather here is always perfect in March, we were told. That’s why people pay twice as much to come then.

You know what happened next. A line of fat squalls sprayed cold rain onto our guests’ unprotected heads. By the time the lasagna came out, the temperature had plunged fifteen degrees. We did manage to scrounge up four patio heaters somehow, around which the jacketless masses could huddle. We were shocked and upset— again—by freaky weather. But just like our sub-Arctic celebration, the crowd’s good spirits soon prevailed. Both ceremonies went on as planned. Cakes were cut, dances were danced, and good times were had by all.

I shouldn’t have been so surprised. While there will always be some weird weather happening somewhere, my wedding experiences were consistent with everything we know about the statistics of climate change. I had described such phenomena many times (though as probabilities, not specific occurrences) to thousands of students in my lectures at UCLA. From my research and travels to the NORCs, plenty of people had told me about bizarre rains in the depths of winter. After a while I’d even become bored with it—one can only listen to so many bizarre- weather stories before it just isn’t new information anymore.

In the previous chapter, we explored how the statistical norms of flood and drought frequency are changing, and how they might become more intense in the future. Now it is time to discuss rising air temperatures in the North—even in the dead of winter and at very high latitudes. Indeed, this phenomenon is a central interest throughout the rest of this book.

Four facts about global climate change need to be made very clear.

The first is that any process of climate change—both natural and man-made—unfolds erratically over time. In fact, its behavior is not unlike that of the stock market.

As every investor knows, long-term trends in the stock market are overprinted with short-term fluctuations. We don’t normally assume that share prices will move smoothly up or smoothly down. Instead, and usually within days, we expect they will reverse, before reversing again, and so on. Wise investors accept this short-term volatility as being largely unpredictable, yet bank on the existence of an underlying long-term trend to guide their overarching portfolio strategy. They say that while short-term markets react to unpredictable things like profit-taking, news reports, and God-knows-what, a long-term trend is more fundamental. And indeed, they are right. Throughout modernity the long-term trend has been for stock values to rise. Its underlying driver is growth of the real economy, fueled by the steady rise of human population and prosperity.

The long-term trend for the Earth’s climate, for at least several centuries, is rising air temperatures in the troposphere (lower atmosphere). Its underlying driver is radiative forcing commanded by the steady rise of carbon dioxide and other greenhouse gases produced as by-products of human activity. Because carbon dioxide, in particular, can linger in the atmosphere for many centuries this buildup is, for all intents and purposes, permanent.²⁷³ Over the long haul, the world’s global average temperature must go up. As shown in Chapter 1, the physics of this has been known since Svante Arrhenius’ work in the 1890s.

Beyond this broad, average trend, however, the warming process gets more complicated. Our planet is not simply a dry rock with a sunlamp shining on it. The additional heat trapped by greenhouse gases is absorbed, released, and moved around the planet by sloshing ocean currents and turbulent air circulation patterns. Living things breathe air in and out, and store or release carbon—a fundamental ingredient of CO₂ and CH₄ greenhouse gases—in their tissues. When the ground is bare, it absorbs sunlight, causing local heating. When snow-covered it reflects, causing local cooling. Volcanic eruptions punch aerosols into the stratosphere, shading and cooling the planet for a few years until they dissipate.²⁷⁴ The energy output of the Sun waxes and wanes slightly. All of these little and not-so-little natural mechanisms and feedbacks are to climate change what profit-taking, insider trading, and short sellers are to the stock market. They muck up the underlying greenhouse forcing trend, overprinting it with shorter fluctuations that rise and fall, then rise again.²⁷⁵ If not for this natural variability, we’d have caught on to the deeper greenhouse signal even sooner than we did.

Any competent financial planner will tell you that the road to secure retirement is paved with market drops. Any competent climate scientist will tell you that our road to a hotter planet will be paved with cold snaps, even record-breakers. But unfortunately, when it comes to communicating this to the general public, we scientists have done a poorer job of it than financial planners. Perhaps it’s not surprising, therefore, that so many people will glance outside at the bitter cold and scoff at global warming—even as they log on to E-Trade to buy up the latest stock market dip.

The second important fact about climate change is that its geography is neither always global nor always warming. To be sure, it is mostly global and mostly warming. But because of the many complex natural mechanisms and feedbacks that inject themselves into the process, the final climatic manifestations of greenhouse forcing vary greatly in spatial pattern. Climate change is not only erratic in time, like the stock market, but also in geography. A globally averaged temperature increase of one degree Celsius does not mean temperatures rise everywhere around the globe by one degree Celsius. That’s just the average. Some places will heat up a great deal, others won’t or might even cool. Summing them all together gets you to the +1°C global average. But that seemingly small number masks some stunning differences around the world.

Consider the map below. It is a projection of our future temperature changes by the middle of this century. Some places are warming hugely but other places hardly at all.²⁷⁶ Why is this? Has some climate model gone haywire?