Massive geoengineering projects may be sexy but they’re not the only way to combat global warming.
Global carbon emissions keep rising and climate catastrophe comes closer every year. Some think the answer lies in grand-scale geoengineering, such as orbiting massive mirrors around the planet, ramping up nuclear power, and spraying sulphur into the sky to seed clouds. But all of these ideas would cost enormous sums of money to implement and are fraught with risks: For example, though adding sulphur to the atmosphere would block sunlight and reduce warming, it would also precipitate acid rain. So before we jump to extreme measures, let’s review the very simple and risk-free actions we can and should take to combat climate change.
1. WHITE ROOFS
If we painted all the roofs in 100 tropical cities white, we would reflect enough sunlight back to space to offset the equivalent of 44 billion tonnes of carbon dioxide, more than one year’s worth of global carbon emissions. It would also improve smog and air quality (and the associated health care costs), and save $30 billion in energy every year. So why on earth shouldn’t we do it, asks Hashem Akbari of the Lawrence Berkeley National Laboratory, who published a paper last year in the journalClimatic Change estimating the “remarkable global cooling potentials” of white roofs in hot cities, covering just “one per cent of the land area of the globe” would reflect enough sunlight to offset the “equivalent to all the world’s cars,” he says.
This wouldn’t be a permanent solution to our climate problems – but it would buy us enough time to slow global warming while we shift our energy supplies to less fossil fuel intensive sources.
2. BIOCHAR
Take organic waste – from kitchen scraps to waste paper, shell husks to dog doo – heat, add to soil, and presto: we have an instant climate solution, no strings attached.
Mixing biochar – a black, porous material similar to charcoal – into soil slows global warming in two ways: First, by trapping the carbon in the organic material and preventing it from escaping as methane when that matter would decay; and second, by enriching the soil and fostering the growth of plants that absorb carbon from the atmosphere. The International Biochar Initiative estimates that we could offset at least one billion tonnes of carbon annually by 2030.
We can create biochar with super hot high-tech kilns, producing energy at the same time—but we can also go low-tech and low-cost. Farmers in the Amazon created biochar with old-fashioned fire more than 500 years ago, and the soils they enriched hold up to 70 times more carbon today than non-enriched soils.
And biochar-steeped earth also holds more nutrients, which not only releases less nitrous oxide (an extremely potent greenhouse gas) into the atmosphere, but also causes less nutrients to flow into rivers and lakes where they spawn dead zones.
For good reason, author and climate action advocate Tim Flannery says biochar “may represent the single most important initiative for humanity’s environmental future.”
3. FARMING THE OCEAN
Planting kelp farms on just four per cent of the ocean surface would soak up 70 percent of the carbon dioxide we emit every year, says Mark Capron of PODEnergy. And then digesting the kelp in giant plastic bags can produce methane, a “natural gas” we can use for energy, before the processed kelp is buried on the ocean floor to lock the carbon away.
Plus, creating huge kelp forests would create valuable habitats for the fish and other sea life that have been overharvested. Win-win.
4. EAT LESS MEAT
Livestock, when you factor in transportation, deforestation to create land for grazing, and methane and nitrous oxide emissions from animal waste, accounts for one-fifth of our global greenhouse gas emissions, according to the United Nations – more than transportation. So if halving our collective meat consumption would cut that down to 12 percent, then reducing everyone’s intake down to just one meal a week would be even more effective.
Our bodies would thank us, too: cardiovascular diseases and strokes kill 17 million people a year and at least 400 million people are obese, according to the World Health Organisation.
Due to China, India and other developing nations aspiring to western lifestyles, the global appetite for meat is set to double by the middle of this century. So maybe we should set a new trend before our cravings create a climate crisis. Already the town of Ghent in Belgium has declared Thursdays meat-free.
5. AXE TROPICAL DEFORESTATION
Speaking of meat: 80 percent of deforestation in the Amazon has been in the name of creating grassland to graze cattle.
Worldwide, deforestation accounts for about a quarter of our greenhouse gas emissions – first by removing the trees that absorb carbon from the atmosphere, and second, by allowing carbon trapped in soils to escape to the atmosphere.
So halting deforestation would be by far the most important thing we could do to save the climate.
And in this train of thought…
6. PLANT MORE TREES
Everywhere.