The scientists, the experts on climate, they are doing their best to explain.
Over and over they call news conferences, stand in front of the cameras and speak into the microphones. They state with all the clarity and import they can muster that in the next century the global temperature will increase by at least 6 degrees Fahrenheit (When reading science papers, don’t forget it’s all metric) . Then they survey the reporters, expecting to see shock and fear.
Instead the reporters wait, pencils in hand, for the newsworthy part.
A few degrees of temperature increase just doesn’t sound all that impressive. When most people, including reporters, try to understand what a 6° rise in temperature means, they imagine the difference between a 60° day and a 66° day. Logically enough, they conclude so what?
The mistake they’re making is they’re thinking in terms of “weather,” rather than “climate.” Weather is the temporary atmospheric details of your local area. “The weather is rainy,” versus ”the weather is dry.” The difference between a rainy day and a dry one impacts you only in terms of whether you decide to bring an umbrella or not.
However if you change those sentences to ‘the climate is rainy,’ or ‘the climate is dry,’ you begin to understand. The difference between these two sentences encompasses the difference between a Florida swamp and Sub-Saharan Africa. Climate is the average weather conditions in an area over a long time, hundreds or thousands of years. And as scientists are increasingly discovering, the many aspects of climate –temperature, rain, wind, heat, etc.– are all so intertwined, that if you shift one aspect a little, a lot of others shift accordingly.
So if you want to understand why the scientists are so alarmed about global warming, instead of imagining the weather of a 60° day shifting into a 66° day, picture the average temperature of the world’s climate shifting. Let’s start with a small shift, say from 60° to 61°. That’s not such a hard example to imagine because up until the last few decades, the global atmospheric temperature of this planet we call home was 59°, quite close to 60°.
It’s important to note first off, not only is the average of 59° relatively comfortable for the planet’s residents as a whole, but perhaps even more importantly, this average has been extremely stable. If you don’t count the last few decades, it’s been 10,000 years since there’s been even two degrees of fluctuation in the temperature. With global conditions this consistent, regional conditions tend to be more consistent also: the range of temperature, the date of the first frost, etc. In the midst of such long-term stability, species can adapt better to the local conditions. Evolutionarily, they snuggle their butts into the stable couch of their local climate and get comfy. Increasingly well-designed for the particularities of their climate, they flourish.
But after 10,000 years, we humans invented the smokestack and tailpipe. We began to spew carbon into the atmosphere at an increasing speed, tucking a blanket of smog in around the planet’s neck, warming the world up a little more than one degree. What harm could a little change like that do?
First, logically enough, the increased heat means increased evaporation. In the hotter air, the soil dries out just a little faster; the water is sucked up into the air, into the clouds. Globally, the frequency and intensity of droughts have been increasing, as well as the frequency and intensity of rain.
Second, if you think of heat the way a physicist would, you understand we aren’t just warming up the world, but we’re ‘increasing the energy in the system.’ Remember your high-school physics textbook, all those diagrams of air molecules bopping around. Picture them heated up a fraction more, bouncing around a little more frantically. When you think of an entire planet worth of molecules, you begin to get an idea of how much energy we’ve pumped into the system. That energy needs to get released somehow.
It’s increased in power and variability. This stronger wind blows the hotter air across the soil, drying it out faster, exacerbating the droughts and thus the rain. The now-heavier rainstorms are also being pushed along by the wind faster, sweeping into a region quicker than before. And the destructive potential of the wind --tornadoes and hurricanes--- has been magnified.
And since we’re on the subject of hurricanes, you should know they can form only over water that is 80°or warmer. A tropical rainstorm with its feet nestled comfortably in 80° water can begin to escalate. Deriving its power partly from the heat of the water, it can scoop up more and more wind, begin to swirl round into a massive circling knot of increasing violence.
A tropical storm with its feet in water that’s just a little cooler, say 79°, can forget all its ambitions. It’s staying just a rain shower.
What we’ve done with a twist of the global thermostat is heat up the oceans as well as the atmosphere. Actually, the oceans have been heating up a lot faster than the air, the seas selflessly swallowing a majority of the heat and CO2 we humans have so frenetically pumped out. A recent paper by Sydney Levitus from the National Oceanic and Atmospheric Administration has shown that the oceans have warmed well over 10 times faster than the atmosphere has. What do you get from these much warmer oceans? A) A much larger geographic area over which the seed of a hurricane can form. B) A much greater expanse over which the hurricanes can travel, continually gaining strength from the warmer water.
You want to know why a Katrina-level hurricane hasn’t hit New York City or Boston? By the time a hurricane travels that far North, it’s been dragging its feet through cold water for a long time. It’s a withered remnant of what it once was.
But the oceans are warming so fast.
I’ve got some advice for people living in all those coastal cities that have never seen a real hurricane before, I’d walk down to the harbor during the summer, during hurricane season, and stick a thermometer in the water. Remember that 80° mark. Remember what New Orleans looked like afterward. You should know also that the houses down in the Gulf have a different building code. The roof supports, the way the shutters are attached, it’s all designed with hurricanes in mind. Even the shacks of the poor legally have to be built to withstand winds people in New England have never imagined. If a sibling of Katrina gets a warm-water path up to the north, the destruction will be immense.
Munich Re is the world’s largest reinsurance company. It’s the one that ends up paying for any violent twitch in the planet’s weather patterns. According to its figures, the worldwide natural disasters for the decades between the 1940s and 60s all cost about the same when adjusted for increases in inflation and population. After that though, it’s like a switch was clicked. The weather-related natural disasters for the 1970s cost almost twice as much as the 1960s.
The 1980s cost five times as much as the1960s.
The 1990s 15 times as much.
Think about that. Put those figures on a graph. X axis = time, Y axis = expenditures. Connect the dots, then follow the direction of that line to where it leads. Up up up into the air we’re so busy polluting.
So far, the planet’s fever is just a little bit more than 1°.
By the end of this century, as the scientists said, the minimum its fever will be is 6°.
So with all these changes --greater heat, greater drought, greater rain intensity, greater wind and more extreme storms-- what happens to all those organisms that have evolved in their comfy evolutionary niches, relying on the relative stability of their local climates? Each of them, they struggle to adapt as fast as they can, but different species can adapt at different speeds, with different levels of ease. Let’s take the sand eels in the North Sea, off England. As the water’s heated up, they’ve adapted pretty easily. They’ve swum north toward cooler waters. For them the problem’s solved. In just a few years, they’ve shifted their habitat a long way north of the most northern shores of Great Britain. Unfortunately, they were the base of the food pyramid in the North Sea. They’ve left a lot of land-based species in the lurch. These species can only migrate as far as the northernmost British isle. After that, there’s no land to nest on. So, last year when the baby sea birds along the English coast hatched (skuas, arctic terns, etc.), their parents flapped off to catch some sand eels to feed to their babies, exactly as North Sea birds have done for millennia. But for the first time, they found there was nothing out there. The ocean empty of their prey. The resulting devastation has been intense. The 1,200 guillemots on the isle of Shetland had not a single surviving fledging.
The scientists have coined a term for this breakdown in the predator-prey relationship, “trophic cascade,” the damage rippling up the food pyramid.
Perhaps in terms of adaptation, trees are in an even more difficult position. Imagine a pine tree. It can’t tug up its roots and lumber toward cooler latitudes as the world’s temperature increases. It can’t even lob its seeds hard in a northward direction. All it can do is watch its pinecones drop right by its roots and hope some passing squirrel or human will kick them a little toward the north. By looking at historical records of how fast trees have migrated, botanists have found the average speed is under 10 miles per century. That’s not nearly fast enough. In 100 years, the city of Boston for example is projected to move south to something close to the climate of Georgia**. That’s 1,000 miles. Wander around in a forest down there; you won’t see a lot of New England trees. Too warm for the pine trees and the maples, the beeches and birches. So how can these trees react as the heat index increases?
They can get sick. Fungus, beetles and arboreal infectious diseases of all kinds are already intensifying because the summers in New England are getting longer, allowing these organisms to squeeze in more breeding cycles. This increased number of parasites will have an easier time finding food as more trees sicken and die from the heat; this in turn will breed more parasites. Vicious cycle. The dead trees serving as vast Petri dishes to grow more diseases.
If you’re in New England, look out your windows. There’s a huge fungus epidemic on maple trees right now because the rain this summer has been about double the average.
And from my unofficial survey of pine trees, about 20% of them look browned at the edges, singed by the heat and/or bark beetle infestations.
Prognosis? The EPA commissioned a report a few years ago that predicted in New England 30% to 60% of these tree species would die by 2100.**
I’m a writer. I’m interested in terms; I think they matter. The best term I’ve heard for what we’re doing to the planet is not ‘global warming’ (because some places will actually get colder as the climate variability increases), and not ‘climate change’ (because ‘change’ is as euphemistic for what we are doing to the Earth as ‘passing on’ is for death). The best term I’ve heard is ‘climate disruption.’
Disruption gets the message across. It sounds bad, sounds unhealthy, something to avoid.
And when it comes to that word ‘climate,’ what I’ve been trying to do in this article is clarify the sweep of that word, its power. The scientists, every year they learn more respect for its reach. However we non-scientists don’t tend to get it yet. When we hear the word “tundra” for instance, we imagine cold temperatures and snow. When we hear the word “marine,” we picture waves hitting a beach. We don’t tend to picture all the many interrelated mechanisms of storms and rain and wind that have to function well to create that climate, its delicate balance. Generally we don’t tend to imagine the occupants of a climate. We separate the musk ox from the tundra, the halibut from the sea.
But remember those sand eels and arctic terns, the pine tree and maples.
When you think of climate disruption, picture all your favorite organisms. The ones you plant in your garden, the ones you consume at your dinner table, the ones you hope to catch a glimpse of at a national park, the ones you hug each morning before they head off to school.
We are all as much a part of the climate as the wind is and the rain. The disruption we are causing will be felt far and wide.