by Alok Jha
In the same year, Kerry Emanuel, a hurricane expert at the Massachusetts Institute of Technology, found that the intensity and duration of major storms around the US had jumped by around 70 percent since the 1970s. “My results suggest that future warming may lead to an upward trend in tropical cyclone destructive potential, and—taking into account an increasing coastal population—a substantial increase in hurricane-related losses in the twenty-first century,” he wrote in Nature.
A hurricane seen from space shows the true size of these enormous storms. The gale-force winds circle around a relatively calm eye and the whole thing is powered by heat from the surface of the sea.
A hypercane, to use Emanuel’s words, is a “runaway hurricane” that can inject large amounts of water and dust into the middle and upper stratosphere, where it will have “profound effects” on the climate and thus on the ability of life to survive.
In a 1995 paper in the Journal of Geophysical Research, Emanuel modeled the conditions required for such a nightmare storm to start. He found that a hypercane could begin if an area of sea just 50 km (30 miles) across was heated to more than 45°C. The resulting 1,100 km/h (700 mph) winds would blow around an eye where the pressure might be as low as 30 kilopascals (normal atmospheric pressure is just over 101 kPa), giving the storm a lengthy lifespan. Conceivably the eye could be hundreds of miles across and the storm itself could stretch for thousands of miles.
For comparison, the largest storm ever recorded in modern times was Typhoon Tip in 1979, where winds blew at around 300 km/h (190 mph) and the central pressure was 87 kPa. The extreme conditions needed to form a hypercane, suggested Emanuel, meant that such storms would probably be limited to tropical regions.
Stratospheric damage
The aftermath of big storms every year makes it abundantly clear that winds, storm surges and floods are devastating to people who suffer them. Hypercanes would be much bigger, and their potential for direct damage therefore greater. But what makes them especially dangerous to our global survival is the damage they do to the upper reaches of the atmosphere, 20 kilometers above our heads.
“The most significant characteristic of hypercanes, from the standpoint of environmental impact, is their ability to inject large amounts of mass in the middle stratosphere,” wrote Emanuel. A ring of air between 5 and 32 km (3 and 20 miles) across, traveling up to an altitude of 20 km (12 miles), would bring with it around 107 kilograms of water per second to the middle stratosphere. Within 20 days, this layer of air would be saturated with water and we would see clouds very high up. Unfortunately, these would certainly not be benign.
For a start, dust and aerosols would cover the Earth, reducing the amount of sunlight getting to the surface. In an odd way, though, that would not be the main problem. The injection of large amounts of water into the stratosphere could have significant consequences for the chemistry of that region. Water molecules would split into a soup of highly reactive free radicals, molecules that have spare electrons (or need one to fill their outer orbits), which can tear other, normally more stable molecules apart. In short, water vapor in the stratosphere would destroy the ozone layer.
The water droplets in the clouds themselves would also catalyze a new set of reactions, activating chlorine that came up with the seawater and deactivating nitrogen oxides. This makes the destruction of ozone even more efficient—and is the mechanism through which the Antarctic ozone hole first appeared.
With the ozone layer depleted, the Earth’s surface and all its living things would be at the mercy of ultraviolet rays. Everything on land and in the upper reaches of the oceans would soon die. With no plants and no animals, eventually very few humans would be left either.
Is it likely?
Emanuel’s conditions for the formation of hypercanes are considerably warmer (some 10–15°C higher) than any recorded measurement of sea-surface temperature, and even with climate change raising water temperatures around the world, it is unlikely that a tropical sea would reach a sea-surface temperature of 45°C on any sort of regular basis. Instead, a hypercane is likely to be the icing on the cake of another world-ending spectacle: an asteroid strike or massive undersea volcano. Emanuel calculated that a hot spot in the ocean was most likely to occur if a ten-kilometer (six-mile wide) asteroid were to hit a shallow sea. Either that, or if a huge underwater volcano erupted and the water above stayed sufficiently calm long enough for the hypercane to build up.
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With no plants and no animals, eventually very few humans would be left either.
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This could be how the dinosaurs were wiped out. Emanuel believes that the asteroid that smashed into the Yucatan peninsula in Mexico 65 million years ago might have caused a hypercane that resulted in the death of most of the world’s species. At the time, there was a shallow sea in the area, which would have been pushed to one side when the asteroid struck. The water would then have rushed back into the hot crater and warmed up to the level needed for a hypercane. Hence the global devastation that resulted.
Sun Storms
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Our advanced, interconnected world depends on fast electronic connections between people in different countries, powered by the electricity grid. These two networks, built up and improved over several decades, have brought us the on-demand world that we take for granted. It would take something huge to knock all of that out of action, wouldn’t it? Well, our planet orbits the thing that could do just that.
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The Sun regularly has Earth-sized storms on its surface that end up ejecting dangerous radiation and particles into space. Mostly these dangerous bits of energy head off into deep space. But what would happen if the Earth got in the way? You could kiss goodbye to the Internet and your electricity supply. Banks and governments would not be able to function. Satellites would be blinded. A storm on the Sun could take us back to the Stone Age.
What is a solar storm?
Without the endless supply of energy raining down from the Sun, there would be no life on Earth. That does not mean, however, that our star is some all-benevolent orb that only gives out goodness.
The Sun, like any other star, is a furious mass of gases with unimaginable energy, which emits radiation of all kinds, ranging from the stuff that plants can convert to sugar through photosynthesis, to high-energy particles and rays that would tear apart anything they came across on Earth.
The Earth, for its part, has a security shield to stop the nasty stuff getting in, while letting through the energy that happens to be beneficial to life. This shield, called the magnetosphere, diverts the worst of the Sun’s radiation, preventing it from reaching the delicate molecules of life on the Earth’s surface. Normally, all we see of this high-energy radiation are the shimmering Northern Lights, the aurora borealis, and its southern equivalent, the aurora australis.
On occasion, however, the Sun will throw out something more than the usual radiation. Magnetic storms on its surface can end up causing flares, explosions that release in one go as much as a sixth of the Sun’s entire output per second. If the storms are particularly strong, they will erupt into coronal mass ejections (CMEs), huge clouds of plasma traveling at 8 million km/h (5 million mph), consisting of energetic electrons and protons with smaller amounts of helium, oxygen and iron.
If the effects of these extreme events were to reach the Earth, the results could be deadly—shutting down power grids, disabling satellites and interfering with electronics. In addition, aircraft flying at high altitudes could be exposed to increased levels of dangerous radiation.
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Banks and governments would not be able to function. Satellites would be blinded. A storm on the Sun could take us back to the Stone Age.
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In a typical scenario, a solar flare on the Sun would be accompanied by a burst of electromagnetic radiation (including radio and visible waves in addition to more dangerous gamma, ultraviolet and X-rays) that, when it arrived on Earth, would
ionize the outer atmosphere. People on the ground would be safe, but GPS and other satellites would be affected. “GPS is a critical part of almost everything we do,” says Thomas Bogdan, director of the Space Weather Prediction Center in Colorado. “The ubiquitous need for an uninterrupted power supply, satellite-delivered services—every time you go to a gas station and purchase a gallon of gas with your credit card, that’s a satellite transaction taking place—and, of course, aviation and communications. We have made our lives increasingly dependent on these things, but each of them carries vulnerabilities to space weather with them.”
Two prominences erupt from the surface of the Sun, captured by the SOHO satellite in 2003. The one on the right (and possibly both) were associated with a flare and a coronal mass ejection that blasted away from the Sun at about the time of this image. The prominences extend a distance of about 20 Earths out from the Sun.
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Space weather can affect human safety and economies anywhere on our vast wired planet, and blasts of electrically charged gas traveling from the Sun at up to 5 million miles an hour can strike with little warning.
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Around 10–20 minutes after the initial flare would come a burst of energetic protons. “Now at risk would be satellites at geostationary orbit—if they do not have sufficient shielding around their sensitive electronics, they could be subject to problems with the internal computational activities,” says Bogdan.
A further 10–30 hours later, a CME would hit the Earth’s magnetosphere and cause electric currents to surge along oil pipelines and high-tension electricity lines. This might cause blackouts such as the one that occurred in Quebec in 1989. Around large parts of the world, people would see a lightshow in the sky similar to the aurora borealis.
“Space weather can affect human safety and economies anywhere on our vast wired planet, and blasts of electrically charged gas traveling from the Sun at up to 5 million miles an hour can strike with little warning,” warned John Holdren and John Beddington, respectively the chief scientific advisers to Barack Obama and the UK government, in a joint statement in 2011. “Their impact could be big—in the order of $2 trillion during the first year in the United States alone, with a recovery period of four to ten years.”
History is the guide
The largest solar storm on record occurred in 1859. The British astronomer Richard Carrington noticed a succession of freak events, including compasses going crazy and aurorae in the sky as far south as Cuba. There was little electric infrastructure in place around the world at the time, but the solar storm did send currents running along the newly built telegraph systems. “They were so strong that the operators of the telegraphs could disconnect their batteries and still start sending messages,” says Bogdan.
Holdren and Beddington outline further events. “In 1921, space weather wiped out communications and generated fires in the northeastern United States. In March 1989, a geomagnetic storm caused Canada’s Hydro-Quebec power grid to collapse within 90 seconds, leaving millions of people in darkness for up to nine hours. In 2003, two intense storms traveled from the Sun to Earth in just 19 hours, causing a blackout in Sweden and affecting satellites, broadcast communications, airlines and navigation.”
The 1989 storm, in particular, has gone down in history as an example of what can happen to modern infrastructure. “On Friday March 10, 1989, astronomers witnessed a powerful explosion on the sun. Within minutes, tangled magnetic forces on the sun had released a billion-ton cloud of gas. It was like the energy of thousands of nuclear bombs exploding at the same time,” says Sten Odenwald, an astronomer at NASA. “The solar flare that accompanied the outburst immediately caused short-wave radio interference, including the jamming of radio signals from Radio Free Europe into Russia. It was thought that the signals had been jammed by the Kremlin, but it was only the sun acting up.”
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It’s reasonable to expect there will be more [solar storm] events. The watchwords are predict and prepare.
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On 12 March, the CME finally hit the Earth’s magnetic field, causing a huge geomagnetic storm. There were spectacular lights in the sky, but on the ground, the particles were inducing currents in the power grids of North America. “Just after 2:44 a.m. on March 13, the currents found a weakness in the electrical power grid of Quebec,” says Odenwald. “In less than 2 minutes, the entire Quebec power grid lost power. During the 12-hour blackout that followed, millions of people suddenly found themselves in dark office buildings and underground pedestrian tunnels, and in stalled elevators. Most people woke up to cold homes for breakfast. The blackout also closed schools and businesses, kept the Montreal Metro shut during the morning rush hour, and closed Dorval Airport.”
Meanwhile, in space, NASA’s TDRS-1 satellite spun out of control for several hours, and space shuttle Discovery had mysterious sensor problems on the high-pressure tanks that supplied hydrogen to its fuel cells.
Is it likely?
At the 2011 meeting of the American Association for the Advancement of Science in Washington DC, John Beddington made an unequivocal statement: “This issue of space weather has got to be taken seriously. We’ve had a relatively quiet [period] in space weather and we can expect that quiet period to end. Over the same time, over that period, the potential vulnerability of our systems has increased dramatically. Whether it’s the smart grid in our electricity systems or the ubiquitous use of GPS in just about everything these days.”
Jane Lubchenco, administrator of the US National Oceanic and Atmospheric Administration, agreed. “It’s reasonable to expect there will be more [solar storm] events. The watchwords are predict and prepare.”
Their calls for more action came with a warning. Solar storms can happen at any time, but tend to become more severe and more frequent in roughly 11-year cycles. The peak of the current cycle is expected around 2013. Since the last peak in activity, the world’s reliance on electronic technology—and therefore its vulnerability to space weather—has increased substantially.
“A study by the Metatech Corporation in 2008 showed that a repeat of the 1921 solar storm today would affect more than 130 million people with sudden and lasting ramifications across the US social and technical infrastructure,” said Holdren and Beddington in their 2011 statement. They added that a recent report by insurance market Lloyd’s of London stated that “A loss of power could lead to a cascade of operational failures that could leave society and the global economy severely disabled.”
What can we do?
Monitoring the activity of the Sun more closely is one part of the equation. The time it takes for the worst bits of a solar storm to travel from the Sun to Earth does give authorities a window of opportunity to get ready for the coming electromagnetic disturbances.
Meanwhile, power companies could prepare by hardening transformers at substations and installing capacitors to soak up current surges that would result in serious problems. Critical satellites should be shielded—though this is something of a balancing act, since every pound of extra weight increases the amount of money and fuel it takes to get the satellite into space.
“Some of these measures can bear fruit quickly, while others will pay off over the longer term,” say Holdren and Beddington. “What is key now is to identify, test, and begin to deploy the best array of protective measures practicable, in parallel with reaching out to the public with information explaining the risks and the remedies.”
Polar Shift
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The Earth’s orientation and orbit around the Sun is critical in ensuring that life everywhere gets the energy it needs thrive. But what if that relative position started to drift, and the Earth began to topple over?
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As long as we keep moving around the Sun and all get a share of the life-giving energy from our star, as long as the seasons carry on as normal so that plants can grow and provide us with food, oxygen and aesthetic pleasure, we can largely forget about the Earth’s
specific movements in space.
But when you start thinking, you realize a few important things. The diversity of life on Earth is a result of a long chain of specific circumstances, such as the chemicals available in a particular pond at some point in pre-history, which kickstarted the evolutionary process. Outside all of that is one crucial and overriding condition: the position of the Earth relative to the Sun at all times.
The Earth’s particular orbit around the Sun is one of the key factors in determining the climate on our planet. For the first organisms to emerge from the primordial soup 4 billion years ago, the distance from the Sun and the tilt of the Earth’s axis had to be just right. For the myriad organisms to have subsequently evolved and flourished, the conditions on Earth had to continue to be right. For life to continue, the conditions will have to stay right.
But the Earth will not remain in the same place relative to the Sun forever. In fact, it is always moving.
How the Sun heats the Earth
Our planet has an almost circular orbit around our star, and the extent to which this orbit departs from a perfect circle is measured by a number known as the “eccentricity.” This value changes over hundreds of thousands of years as the Earth is buffeted by the gravitational fields of other planets, particularly Jupiter and Saturn. A low eccentricity means an almost circular orbit, whereas a high eccentricity means that the orbit is slightly elliptical, so there is a wider variation throughout the year in the Earth’s distance from the Sun and, therefore, the total amount of energy falling on the surface over the course of the year.