Science·What on Earth?

To feed the world amid climate change, we need a better way to grow rice

In this week's issue of our environment newsletter, we look at a more sustainable way of growing rice and we get straight talk from a young activist at the climate conference in Poland.

Also: Your suggestions for greening the holidays

(Sködt McNalty/CBC)

Hello, hello. This is our weekly newsletter on all things environmental, where we highlight trends and solutions that are moving us to a more sustainable world. (Sign up here to get it in your inbox every Thursday.)

This week:

  • A more sustainable way to grow rice
  • 'We have lost the luxury of time': A youth activist reports from COP24
  • The world's smoggiest cities
  • Your suggestions for how to make the holidays greener

Growing rice in an age of climate change

(Erika Styger)

Humans have been growing rice for millenniums, so it can seem ignorant to say there's a better way to do it.

Yet, for decades, there's been a method that breaks from the norm and claims to do more for farmers and less to hurt the environment. It's called the System of Rice Intensification (SRI) — and climate change may finally drive it mainstream.

But let's back up a little.

The world needs rice. Billions of us eat it, and more than 100 countries grow it. In 2010, global rice production was almost 700 million tonnes. As populations grow in Africa and Asia, so will consumption.

Traditionally, rice seedlings are transplanted from a nursery after several weeks and packed into flooded paddies. A kilogram of rice can take about 2,500 litres of water to grow. That flooded paddy creates an anaerobic environment, where organic material decomposes and creates a lot of methane. In fact, the UN's Intergovernmental Panel on Climate Change says between five and 20 per cent of human-caused methane emissions come from rice.

So what's different about SRI? Farmers transplant the seedlings earlier, spacing the plants apart and giving them much less water — even letting them dry out.

Examples in more than 55 countries show the result is a stronger plant that yields more rice and uses up to 90 per cent fewer seeds and 30 to 50 per cent less water.

"The conventional wisdom is still that rice is a water-loving plant. It's not true," said Erika Styger, a leading SRI researcher at Cornell University. In fact, she said if you provide less water, "the roots develop much deeper."

Hardier roots mean greater resistance to drought and other extreme weather events made stronger by climate change. Using less water also drastically cuts methane emissions, although some research suggests dry conditions may lead to the release of nitrous oxide, a more dangerous greenhouse gas.

Other criticisms have been that SRI isn't always reproducible, and that it's more of a loose set of guidelines than a strict scientific method. But Styger said it wasn't designed in a lab. "It came from the farmers," she said. "For farmers, it works."

Indeed, it's farmers who have helped spread it in West Africa, even adapting it to work on crops like wheat. But intensification may have its downsides.

Agricultural intensification "should free up space and reduce deforestation," said Laura Vang Rasmussen, who studies crop intensification strategies at the University of British Columbia. "But it might be so profitable for farmers that we actually might have a situation where [it] escalates the agricultural intensification and expansion of agriculture."

She cites examples in Laos, Uganda and Rwanda, where intensification has not only deforested more land but also degraded the soil and affected biodiversity.

Still, it seems climate change makes SRI a fix to an immediate problem: food insecurity. And in a warming world, how we feed ourselves sustainably will unquestionably demand more of our ingenuity.

Anand Ram

'There is so much more to do': Straight talk from COP24

(Marina Melanidis)

Marina Melanidis recently graduated from the University of British Columbia with a B.Sc. in natural resources conservation. This week, the 23-year-old Canadian is at COP24, the UN climate conference in Katowice, Poland, as part of a B.C. youth delegation. Here's a snapshot of what she's seen.

It's only been three days into my COP24 experience and it is already easy to forget that I have a life outside of this conference. I'm overwhelmed by what's going on: negotiations, high-level meetings, nation pavilions, larger side events and smaller working groups. I've walked by Canadian Green Party Leader Elizabeth May in the hall, blew past federal Environment Minister Catherine McKenna en route to a meeting and heard whispers that Al Gore is here. (He was.) The voices around me are speaking English, Polish, French, Mandarin, German, Arabic and many languages I don't recognize.

COP24 has been concentrated with impassioned reminders about the need to increase our climate action ambition and the frightening reality about what will happen if we don't. "We have lost the luxury of time" is a common speaking point in the dialogues. Yet there is a seemingly intrinsic contradiction between the calls for ambition and the negotiations among countries. Despite the cries for urgency, no one can agree on a followup that adequately matches the ambition required. Countries have not even been able to reach a consensus to recognize the recent IPCC Report outlining the catastrophic impacts humanity will face if global temperatures rise over 1.5 degrees. Instead, to illustrate the host country's dedication to coal, there is a literal shrine to that resource standing in the Polish pavilion, complete with coal soap and coal jewelry (I am not kidding).

COP24 has been overwhelming, and often disheartening. There is so much more to do, and it is clear that many countries and stakeholders are not only unwilling to give up the status quo for our future, but some are actively undermining any increment of progress — such as attempting to exclude the reference to climate change's impacts to human rights within the Paris agreement rulebook.

Yet when I walk through security in the morning, past the "#COP24" sign and into the venue halls, I find the same excitement I've had since I was first selected for this youth delegation. l continue to grapple with the disbelief that I am actually here, surrounded by people from all over the world who are also pushing for climate action.

I don't know if Canada, or the world as a whole, will meet our targets. The current trend to do the bare minimum, to shy away from the bold actions that we desperately need to take, worries me greatly. But when I am sitting down with youth and civil society members from all corners of the globe, discussing and making plans for how we can make the greatest impact in this space, I feel empowered and hopeful.

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Hot and bothered: Provocative ideas from around the web

The Big Picture: The world's most polluted cities

Coal plants, car exhaust and burning foliage are major sources of smog. While a lot of cities have made efforts to reduce the soupiness of their air, the problem persists in many parts of the world. The World Health Organization measures smog as the amount of particulate matter under 2.5 milligrams in every cubic metre of air. By that metric, WHO found that six of the 10 most polluted cities are in India. (In case you were wondering, the least polluted city on Earth is Bredkalen, Sweden.)


It's surprisingly easy being green (during the holidays)

Last week, Emily Chung examined whether it was greener to buy a real Christmas tree or a fake one. With that in mind, we asked you to share the ways you are greening the holidays. You had many insightful responses. We've included some below.

One reader, who asked to remain anonymous, shared the photo below of a natural tree that can be reused every year.

The reader explained that it's "a potted Norfolk Pine, which is tropical. I have had this one for almost 30 years, but it has only recently been used as a Christmas tree. It has grown to be huge, but its branches are not really up to holding significant ornaments, so we just wrap the lights around the trunk, which gives it a decidedly Jamaican flavour after dark! It looks like a palm tree with the lights on! I wrap the pot in green silk and my son sets up his wooden toy train set all around the tree base as more decoration. I only use the very lightest and sturdiest of ornaments on it."

"Brings me joy just looking at the pic," they wrote.

In a similar vein, Brian Wood wrote that "every 10 to 15 years we buy a small live tree and keep it outside in a big plant pot."

Each Christmas, they decorate it, bring it into the house for a few days and then put it outside again. When the tree is simply too big for the house, they plant it in the ground.

"We have done this for over 30 years and have a small tree plantation in our front yard to prove it."

Ruth Gatzke wrote about her eco-friendly gift idea: "I potted up rosemary plants that I grew from seed last summer. I have them in repurposed clay pits with leftover ribbons I found around the house tied to the base. Everyone on my list is getting one."

Gatzke added that her family is not buying presents this year. "No stress — just spending time together is enough!"

Meanwhile, Samantha Salmon said that she has found a better way to package gifts. "One of my ways to green the holidays is to wrap gifts with cloth instead of wrapping paper. To keep it festive, I purchased some Christmas-themed cloth from Fabricland and hemmed it. It looks great!"

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Editor: Andre Mayer | Logo design: Sködt McNalty


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