TROPICAL TROUBLE: Climate change is already shifting the zones in which tropical farmers can best grow certain crops, such as coffee.
Image: Wikimedia Commons/Elberth Andres
When Andy Jarvis wants to explain to locals how future climate change will affect agriculture in the tropics, he uses a familiar landmark: a mountain.
A 2-degree-Celsius increase in temperature -- the anticipated rise from climate change in the next 40 years -- is roughly equivalent to a 500-meter change in elevation, he said. Farmers growing at an elevation of 1,500 meters will need to move crops up to 2,000 meters.
"The reality of that to people is tremendous," said Jarvis, a researcher with the Decision and Policy Analysis program of the International Center for Tropical Agriculture (CIAT) and a team leader with the CGIAR Research Program on Climate Change, Agriculture and Food Security. To many South American or African farmers, "everything that is coffee today will not be coffee tomorrow."
To farmers in tropical regions, climate change has become a tangible reality. CIAT researchers have already found that increasingly erratic weather and high temperatures will change the growing patterns of world commodities like chocolate and coffee. But it will also affect cassava, millet and other crops vital to local populations.
Scientists sometimes struggle to match the tangible evidence of today with the theoretical climate models for the next 50 or 100 years. Earlier this week, scientists Richard Washington of the University of Oxford in the United Kingdom and Mark New of the University of Cape Town in South Africa released studies on West Africa, East Africa and the Indo-Gangetic Plain of South Asia. These studies matched some of the most widely used climate models with projections for future agricultural output.
Instead of providing a nice, neat and clear answer, the findings showed that the effect of future climate change on agriculture is wildly uncertain. While the trends associated with climate change -- hotter days, heavier rainfall and a greater number of extreme weather events -- are present in the models, for many crops in Africa and Asia it's not clear how extensive the effects will be.
This uncertainty is not necessarily a bad thing, but it makes climate science -- especially in relation to a field as vital as agriculture -- difficult to grasp. New, who conducted the study of climate models in the Indo-Gangetic Plain, said it would be problematic to rule out the "less bad" models from the worse ones.
"It's safer to ... be looking at the full range of uncertainty in the models rather than picking and choosing," he said.
Dealing with the unknown
The "U word," as Jarvis calls it, is an uncomfortable one for those who don't work with it daily. Yet it is something that ordinary citizens deal with daily without knowing.
"The reports are being completely open and honest about uncertainty," said Jarvis. Although daunting in the context of climate change, most people have learned to use weather forecasts to make decisions for everyday life.
"You can come up with hundreds of decisions," said Jarvis. "It's always built on partial information."
In general, African crops like banana, cassava, pigeon pea and rice respond well to high temperatures, and the areas of optimal growth for those crops could expand. Corn, millet, potato, sorghum, sweet potato and wheat have a lower temperature threshold for success, and yields are likely to diminish as temperatures rise. In South Asia, water availability and rainfall seem to be more limiting factors than heat for corn, wheat and rice.
On the ground, the effects already exist. A 2-degree temperature increase in Peru would limit the potato plant's ability to produce tubers, the edible root of the plant, said Jarvis.
Another root plant, cassava, is a staple crop in West Africa. Its future is also uncertain. While the study released by Washington shows that it will be one of the most resilient crops in the face of climate change, Claude Fauquet, director of the International Laboratory for Tropical Agricultural Biotechnology at the Donald Danforth Plant Science Center, believes that drier temperatures in West Africa will hurt yields, but cassava will see more productivity in central and southern Africa. CIAT is currently studying the crop's viability.
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13 Comments
Add CommentInteresting disconnect between the article and the title. The title indicates tangible reality while the article talks about the very wide range of uncertainty. Why must the editors create such a disconnect? Difference between journalistic politics and scientific inquiry.
Reply | Report Abuse | Link to thisWill the warmists every use the real planet and its atmosphere for analysis instead of their fantasy planet in their computer models? So far, your models have predicted heat from the last decade that never appeared. So it is likely the next 50 years of "predictions" are just as wrong because the warmists still don't accept their theory is flawed. What is sad is it might even be true but the warmists are so caught up in their religious like fanaticism that the planet is warming and only caused by CO2, they are probably missing something legitimately wrong. So then they take their ridiculous models and look around the planet for "proof" they are right (not look at all data to determine if their theory is right or wrong, just right) and they find "erratic" weather as if the weather has not been erratic before the industrial age. Then we get to the outcomes, the constant claim that somehow all the water on the planet will disappear causing drought everywhere, yet at the same time flood everywhere, roast everything, freeze everything, make up your minds warmists, how is Armageddon going to happen this time?
Reply | Report Abuse | Link to thisThe only thing the author didn't do was tie the title to the reality of what uncertainty and - more importantly - change means to farmers in these areas. Can you imagine having to move your entire farming operation up or down in elevation? Moving at all could mean an inability to continue farming for many of them or it could be conflict over decreasing arable land either at higher altitudes or over low altitude land that is in use for other crops or already spoken for. The author should have delved into what that means for these farmers. Uncertainty and change /are/ hard times for the vast majority of human beings on this planet.
Reply | Report Abuse | Link to thisYou are really creating a straw man argument Priddseren. You are taking a bunch of climage changes which are going to happen in isolated spots on the planet and saying that global climate change has to be only one of those or none of those. There will be places where water will become scarcer and some where it will be more abundant. There will be places where the temperature will go down and places where it will go up. There are places where the temperature will not go consistently up or down but will fluctuate more wildly than ever before. It is actually possible that some places on the planet will be come vastly colder, i.e. the front range of the Rocky Mountains would get much colder if the higher temperatures in the Pacific cause the Jet Stream to turn south. I'm sure the ski areas would love that but there would be many impacts on people living in the area.
Reply | Report Abuse | Link to thisCalling it Global Warming is deceptive and was a mistake on the part of the scientists who originally coined the term. It's really Global Climate Change and also Global Climate Instability brought on by an overall increase in the planet's temperature.
One thing to think about is that the number of times insurance companies have had to call in the core insurers (the mega insurance companies that back up the smaller companies) has increases by an order of magnitude in the last 10 years. The number of billion dollar payouts for catastrophic events has hit record levels. Related to Global Climate Change? Well, ask yourself what else could it be. And also ask yourself if we should maybe err on the side of caution. This is after all the only atmosphere and only planet we have at the moment. Kind of reckless to experiment with it without regard to the consequences.
Are you suggesting that all climate models (the majority) that predict warming due to GHG's are flawed? Being a skeptic is one thing - broadly rejecting a global body of peer-reviewed scientific evidence and branding (apparently) anyone concerned about this issue as a "warmist" demonstrates a lack of understanding at best, or maybe a penchant for highly improbable conspiracy theories?
Reply | Report Abuse | Link to thisRemember that climate models are designed to give us the approximate details and timing of future climate change based on present and predicted levels of GHG in the atmosphere. While these details are important (and subject to error and variables), they are not the be all and end all of predicting climate change, i.e. the consequences of de-sequestering huge amounts of carbon and returning it to the atmosphere are very well understood, if just from the basic physics of the heat trapping properties of the element.
Again, the details are necessarily complex and messy but the overall story is very easy to comprehend...I am also curious whether you discard ocean acidification as a fiction as well? As an "Acidifist" I can tell you that decreasing ocean PH levels are an existential threat to civilization (as we know it) and reason enough alone to decrease mankind's carbon footprint.
The same old strawman about models are the basis of AGW is here again. The topic rarely matters ... the echo chamber only has a few oft-repeated notes.
Reply | Report Abuse | Link to thisThis is the key finding:-
"To farmers in tropical regions, climate change has become a tangible reality."
The rest of Priddseren's gibberish shows as little knowledge of the issues as his opening statement.
What disconect? Hard times ARE comming, like the title says. The article states that we just don't know for sure how bad it will be.
Reply | Report Abuse | Link to thisMore non-science rambling from the warming cultists at 'Unscientific American'.
Reply | Report Abuse | Link to thisAndy Jarvis says...nothing in particular but twist this into another extremist headline with no connection to any tangible research.
priddseren: "make up your minds warmists, how is Armageddon going to happen this time?"
Reply | Report Abuse | Link to thisYes, it's amusing how the GW groupies can endorse a dozen scenarios from the same variables
How can you tell when a Warmist is lying?
Reply | Report Abuse | Link to thisHis or her lips are moving.
Several months ago I put up a comment on how a local debate on development of a mine was hijacked by an Eco-corporation whose representative stated that he would say or do whatever necessary, including lying, to make sure the mine wasn't built. Several posters here slagged me and said that the Warmists don't lie.
Yeah... right.
Typical pro-pollutionist misuse of an old worn-out joke joined at the lips to a rambling piece of idiotic rubbish.
Reply | Report Abuse | Link to thisSo wait, your unsubstantiated claim drew ridicule from others and you're wining about it? Give me a break. Produce the quote and I'll look it up. Produce the name of the "Eco-corporation" (ooohhhh! Scaaaary!) and I'll look that up. You see, this is how a debate is SUPPOSED to work. You bring facts, I look them over and either concede points to you or debunk them. Then I bring facts and the process repeats until we boil down to the irreconcilable differences, if there are any, and agree to disagree on those.
Reply | Report Abuse | Link to thisHowever, I can't even get an acknowledgement that CO2 traps heat out of you deniers. We can't even take the FIRST step in having a debate! So don't start pouting when people call you out on what you actually are: either a paid misinformer of the fossil fuel industry or a closed-minded conspiracy theorist that has a total disregard for the facts!
It is even more amusing to watch deniers adhere to mutually exclusive arguments, so as:
Reply | Report Abuse | Link to thisClimate sensitivity is low; Lindzen's iris effect hypothesis of clouds proves this.
Climate has changed wildly in the past; therefore, it is not our fault this time.
Which is it? If the climate inherently stable, then the library of studies indicating large changes in the past are all wrong.
CO2 is a trace gas; there isn't enough if it to have any effect.
CO2 is saturated; there is so much of it that any more will have no effect.