Category Archives: Climate Change

Farming in an uncertain climate

At least some increase in global temperatures over the next few decades is now generally accepted as inevitable. However due to the still not fully understood nature of our climate and the interplay between its complex feedback systems, models still do not agree on the magnitude of the changes expected on a regional scale. Therefore, policy makers have, more often than not, been avoiding the issue of addressing the climatic affects on future crop yields.

According to a United Nations report, in 2007 agriculture accounted for 45 per cent of the world’s labour force, or about 1.3 billion people. In low-income countries it was slightly higher at 55 per cent with the figure being closer to 66 per cent in many parts of Africa and Asia.

University of Leeds scientist Prof Andy Challinor and co-workers have been working on the issue of how farmers can adapt to a warming world. Case studies from Sri Lanka and Central America illustrate how a “no-regrets” adaptation approach can benefit farming communities regardless of the magnitude and timing of the warming itself.

Sujit Kumar Mondal and his wife Rupashi Mondal of Gopalgonj district in southern Bangladesh working in their floating garden. A no-regrets adaptation. @Peter Murim, IRIN
Sujit Kumar Mondal and his wife Rupashi Mondal in southern Bangladesh working in their floating garden. A no-regrets adaptation. @Peter Murim, IRIN

The “no-regrets” approach to climate adaptation basically starts off by analysing the capacity of socio-economic groups such as communities, industries or countries. Adaptations strategies are then proposed that are both economically and politically feasible over a range of possible climate scenarios.

Sri Lanka

Sri Lanka is a country heavily dependent on agriculture. Current climate model predictions for changes in annual precipitation vary in magnitude and even direction of change, i.e some predict increases in rainfall while others predict a drop for a range of emission scenarios.

Given such uncertain predictions the government of Sri Lanka took a pragmatic approach to climate adaptation. It took into account the current capacity of local farmers to implement cost effective, low risk responses to high vulnerability districts.

Strategies implemented include the restoration of ancient water storage tank systems to harvest rainwater during the wet season to be used later in the dry season, the development of sustainable groundwater usage, adoption of micro-irrigation technologies and waste water reuse. These “no-regrets” changes enable a more sustainable approach to farming for Sri Lanka’s farming communities.

Central America

Arabica coffee beans. Source: Malcolm Manners
Arabica coffee beans. Source: Malcolm Manners

In Nicaragua 14% of the gross domestic product comes from coffee exports. While coffea arabica is the main source of livelihood for many farmers it is a crop very sensitive to climatic conditions. It requires stable temperatures between 19-22 degrees Celsius and little variation in annual rainfall. This translates into only certain altitude bands being suitable for arabica plantations. In Nicaragua this band lies between 400-1400m above sea level while in Columbia it is 1200-1800m.

Most climate models for this region predict a temperature rise over the next few decades but the models do not agree on the magnitude of the increase. For example, a temperature increase of 2 degrees Celcius (one of the more optimistic estimates) would result in a 400m change in the elevation range of the crop, equivalent to a loss of two thirds of the current altitude range.

The “no-regrets” adaptation plan for this region involves a change to a different crop, one more favourable to increased temperatures. At lower elevations arabica can be replaced with cocoa which has a similar cash value and is better suited to the higher temperature conditions. At higher altitudes in regions newly becoming suitable to coffee plantations the environmental impacts of the crop is considered to be too harmful. The region in between must involve a dynamic approach where farmers respond to the changing climate by adjusting their agricultural practices. Incremental adaptations through greater shading and other management practices including diversification will be the appropriate response.

Feeding the future

Despite uncertainties in regional climate forecasts much progress can be made by focusing on what we do know. By assessing the current capacity of local governments and farmers simple adaptation strategies can be implemented that are flexible over a range of probable climate futures. It is clear that as our climate continues to warm the affects on agriculture will become increasingly visible. We must start embracing changes to our agricultural practices and adaptation strategies. With a world even now, under food shortages we cannot afford to remain indifferent.

“Climate projections will always have a degree of uncertainty, but we need to stop using uncertainty as a rationale for inaction,” says Dr Sonja Vermeulen, head of research at Climate Change, Agriculture and Food Security (CCAFS).

Further Reading:


A love poem for the Earth #showthelove

Yesterday was National Poetry Day, so here are some celebrities reading a simple love sonnet. We can protect the planet we love!

“So long as men can breathe, or eyes can see,
So long lives this, and this gives life to thee.”
– Sonnet 18, William Shakespeare

Islamic scholars call for action on climate change

A declaration by Islamic scholars calls on global leaders to reduce greenhouse gas emissions and suggests that Muslims have a religious duty to tackle climate change.

The Islamic Declaration on Global Climate Change, drawn up by a group of academics, Muslim scholars and international environment policy experts, was announced recently at a symposium on Islam and climate change in Istanbul. It calls on the 1.6 billion Muslims around the world to phase out our reliance on fossil fuels and switch instead to clean energy from renewable sources.

The statements reiterates the now well documented rise in global average surface temperatures since the industrial revolution and attributes this increase to excessive burning of fossil fuels.

It states that:
“This current rate of climate change cannot be sustained, and the Earth’s fine equilibrium (mīzān) may soon be lost.”

The declaration laments the slow progress of international climate-change negotiations:
“It is alarming that in spite of all the warnings and predictions, the successor to the Kyoto Protocol which should have been in place by 2012, has been delayed.”

It calls on global leaders, who will be meeting in Paris this December, to come to an “equitable and binding conclusion” and commit to a 100 % renewable energy and/or a zero emissions strategy.

The Islamic declaration follows a similar call to action by Pope Francis in his encyclical Laudato Si’ in June this year.

“All the faiths are talking about climate change,” says David Shreeve (via Nature), environmental advisor to the Church of England’s Archbishop’s Council. “It’s great that the Muslims are putting out a declaration, because whatever your faith, it’s a great opportunity for the faiths to stand up and say we really are concerned about this.”

The declaration ends with a reminder to all Muslims of a verse in the Qur’an –

وَلاَ تَمْشِ فِي الأَرْضِ مَرَحًا إِنَّكَ لَن تَخْرِقَ الأَرْضَ وَلَن تَبْلُغَ الْجِبَالَ طُولاً

Do not strut arrogantly on the earth.
You will never split the earth apart
nor will you ever rival the mountains’ stature.
Qur’an 17: 37

Read the full declaration here:

2015 predicted to be disastrous for corals

The unique biodiversity within coral reefs support the livelihoods of over a billion people, but 2015 is predicted to be disastrous for corals.

China’s carbon emissions may have been overestimated

An analysis of two major sources of China’s carbon dioxide emissions suggests that the country’s carbon emissions may have been overestimated in recent years.

China’s carbon emissions from burning fossil fuels and cement production are significantly lower than previous estimates. About 14% less in 2013 compared to estimates by the Chinese government and others according to research published in Nature this week.

About three quarters of the growth in carbon emissions from the burning of fossil fuels and cement production between 2000 and 2012 occurred in China. These helped to sate China’s booming energy thirst and boost its economy from around US $3,500 GDP per Capita in 2000 to over $8,000 in 2012.

A Chinese coal power plant. Source: WC/Tobias Brox
A Chinese coal power plant. Source: WC/Tobias Brox

The actual amount of carbon dioxide emissions from two major sources: burning fossil fuel and cement production has been plagued with uncertainties. The new study led by Zhu Liu from Harvard University re-evaluates data from 4,200 Chinese mines and incorporates new measurements of the emission factor of coal.

The team found that China’s carbon emissions from these two sources have been consistently overestimated.

“At the beginning of the project we thought that the emissions might be higher” than existing estimates, says Zhu Liu. “We were very surprised.”

Despite these new revisions to carbon emissions China is still the world’s largest emitter of carbon dioxide. Even when the lower estimates are taken into account, China’s carbon emissions for 2013 was still more than two-thirds higher than the second largest emitter, the United States.

Nevertheless, the new estimates represent a substantial decrease in annual global carbon emissions in 2013 by 0.35 GtC (billion tons of Carbon), an amount larger than the reported increase in global emissions between 2012 and 2013.

More information:
[1] Read the full paper here:

“So long, and thanks for all the fish” … the end of coral reefs?

Leading scientist says that even ambitious greenhouse gas reduction targets will not be able to save the world’s coral reefs.

Professor Peter Sale from the University of Windsor, Canada claims that coral reefs, as they were 50 years ago, cannot be saved from climate change – even if the climate change talks in December this year (COP21) are “wildly successful”.

Professor Sale unveiled the depressing results today at the Goldschmidt conference, a gathering of the world’s top geochemists in Prague.

He said, “Even if Paris is wildly successful, and a treaty is struck, ocean warming and ocean acidification are going to continue beyond the end of this century. This is now serious; I find it very unlikely that coral reefs, as I knew them in the mid-1960s, will still be found anywhere on this planet by mid-century. Instead, we will have algal-dominated, rubble-strewn, slowly eroding limestone benches.”

A bleached coral. These events will become more common with global warming.
A bleached coral. These events will become more common with global warming.

Globally coral reefs are generally found in tropical waters. Not only are they some of the world’s most productive ecosystems they also deliver ecosystem services in tourism, fisheries and coastline protection. The global economic value of coral reefs has been estimated to be US $375 billion per year!

Loss of reefs will be a fatal blow for the animals and communities who rely on them

While the global policy debate has been about trying to limit global warming to 2 degrees by the end of the century, Professor Sale claims that this won’t be enough to save coral reefs.

“I see little hope for reefs unless we embark on a more aggressive emissions reduction plan. Aiming for CO2 at 350ppm, or a total warming of around 1°C is scientifically defendable, and would give reefs a good chance; a number of coral reef scientists have called for this.”

Sale summarised:

“Knowing what we are doing, do we have the ethical right to eliminate an entire ecosystem from this planet? It’s never been done before. But watching as our actions lead to the loss of all coral reefs on the planet is like removing all rainforests. I don’t believe we have that right”.

Obama reveals “biggest, most important step” towards tackling climate change

President_Barack_Obama“I believe there is such a thing as being too late.”
– President Obama

Yesterday President Obama unveiled his “biggest, most important step” towards tackling the affects of climate change,

The proposed Clean Power Plan has been billed as the strongest action ever on climate change by a US president.

According to the proposed plans, the U.S. will cut levels of greenhouse gas emissions to a third of 2005 levels in the next 15 years. The measures include significant advancements in solar, wind and other renewable energy sources.

Key points of Obama's Clean Power Plan
Key points of Obama’s Clean Power Plan

“No challenge poses a greater threat to our future, and future generations than a changing climate.”
– President Obama

White House adviser Brian Deese said the Environmental Protection Agency (EPA) rules represented the “biggest step that any single president has made to curb the carbon pollution that is fuelling climate change”

The full press conference can be viewed here:

More information:

The Silk Road helped form a hidden carbon sink under the desert

Scientists have found a potentially large carbon sink in the most unlikely place on Earth – under the desert. The increase in carbon storage is linked with the rise of farming in arid landscapes.

This surprising conclusion comes from work done in the Tarim Basin of western China by Chinese and American scientists. The results are published in the journal Geophysical Research Letters.

“Basically, people thought the whole arid region is totally negligible to the global carbon budget,” says lead author Yan Li of the Chinese Academy of Sciences in Urumqi. “We are arguing that that’s not the case.”

Li and colleagues measured and dated the carbon content of water samples taken from a salty aquifer beneath the Tarim Basin. They show that the rate at which carbon sunk into the aquifer rose dramatically with the rise of farming and agriculture in the region. Rate of carbon storage increased by more than 12 times previous levels over the past 8000 years with particularly high levels beginning around 2000 years ago when the Silk Road opened.

How it works

The process began when humans started to grow crops on sandy soil. As the plants take in carbon dioxide from the air, some is released into the sand. Farming in desert conditions requires a lot of water to combat rising salinity caused by rapidly evaporating water. This organic carbon dissolves in the water and is transported down through the sand into deed salty aquifers.

A schematic diagram showing the leaching and transport of DIC (dissolved inorganic carbon) in a closed arid basin. Source: Li et al, 2015

Normally these aquifers are tapped by rivers and streams and so the carbon comes back out of storage. But in the Tarim Basin the aquifer is a closed system, meaning that water does not escape, effectively locking away the carbon.

Li expects this process to occur in deserts around the globe but the amount of carbon would vary depending on the pH of the soil and the level of farming activity.

The results from this study will have important implications for the study of the global carbon cycle as desert regions were previously thought to be unimportant for carbon storage.

Read the full study here:

Will we lose our crops to climate change?

With the World’s population now past 7 billion and projected to increase to 9 billion by 2050, stress on the food production system is at an all time high. To make matters worse it appears that our crop yields may fall victim to the effects of climate change.

Crop yields to drop by 25 percent towards the second half of the century.
Crop yields to drop by 25 percent towards the second half of the century.

Global warming of only 2°C will be detrimental to the production of rice, wheat and maize in temperate and tropical regions, with reduced yields from the 2030s onwards claims a study, published in Nature Climate Change last year, led by the University of Leeds scientists.

“Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts,” says lead author Professor Andy Challinor.

The study shows that we will see, on average, an increasingly negative impact of climate change on crop yields from the 2030s onwards. The impact will be greatest in the second half of the century, when decreases of over 25% will become increasingly common.

These statistics already account for minor adaptation techniques employed by farmers to mitigate the effects of climate change, such as small adjustments in crop variety and planting date.

The IPCC projected temperature increase for the next century.
The IPCC projected temperature increase for the next century.

The latest Inter-governmental Panel on Climate Change (IPCC) reports state that the expected temperature increase for the end of the century is somewhere between 1.5 and 4 degree Celsius. And thus, major agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations.

Read the full study here:

Climate change explained in 60 seconds

Climate science explained in 60 seconds by the Royal Society and the US National Academy of Sciences.