Studying the Effect of Global Warming on Tropical Crops

Global Warming Effects on Tropical Crops

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Researchers have long been using impact studies to study the effects of climate change on cocoa growth. These studies mimic conditions predicted at the end of the century1 such as higher levels of drought and higher levels of atmospheric CO2.

Studies have shown that increased levels of CO2 may help offset the negative effects of reduced water availability on the growth of cocoa, which means our chocolate bars are safe for now.

How Will a Changing Climate Impact Cocoa Production?

Cocoa, a key ingredient in chocolate is one of the most important perennial crops in the world. It has been estimated that global cocoa production will reach 4.7 million tons in 2017, with most of the cocoa (74%) grown in West Africa.2,3

As global CO2 levels continue to increase, from present levels of 400 ppm to 550-800 ppm at the end of the century, dry areas like West Africa are projected to become drier, with more frequent droughts. So far, not much research has been done to study the effects of increased levels of CO2 and decreased water availability on cocoa and other tropical perennial plants grown.1,4

In order to maintain a sufficient food supply, it is important to identify which type of plants may be best suited to new conditions and how plants will respond to climate change. To fully understand how changes in water availability and CO2 caused by climate change have an impact on crop growth and food availability, Researchers usually grow plants in conditions that mimic the predicted atmospheric conditions at the end of the century.

Since CO2 is the primary substrate for photosynthesis, increases in atmospheric CO2 is also expected to increase the plants growth rates by an average of 38%. However, plant growth rates may reduce by reduced water availability but at the same time increased rates of photosynthesis usually improve water-use efficiency in plants, which means the negative impacts of reduced water availability could be alleviated by increased CO2 levels.1,5

Studying How Increased CO2 Impacts Crop Growth

UK Researchers have studied the combined effects of water deficiency and increased CO2 levels on the growth of cocoa and have reported that elevated levels of CO2 lowered the negative effects of reduced water availability. The Researchers grew cocoa in greenhouse compartments with different water levels and CO2 concentrations, and then measured the photosynthesis and growth rates of the cocoa plants. They discovered that in elevated levels of CO2, the growth of cocoa plants increased by roughly 50% in both water-deficit plants and well-watered plants when compared to cocoa plants grown at ambient CO2 levels.1

The UK team observed that climate change conditions indeed had a positive impact on cocoa growth, but the effects of other changes associated with climate change have not been fully studied yet. Further, climate change may have several implications for the growth of crops like cocoa including O3 pollution, flooding, temperature changes and the impact of climate change on pests and diseases. However, the collective effect of all these factors is yet to be known.1,5

CO2 Effects on Crops

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CO2 Sensors for Climate Change Impact Studies

Researchers investigating the effects of climate change on plant growth will require highly accurate CO2 measurements. The UK Researchers used an Edinburgh Sensors CO2 sensor in their greenhouse to provide reliable and precise CO2 measurements. As a customer-focused provider of high-quality gas sensing solutions, Edinburgh Sensors has been providing gas sensors to the research community since the 1980s.1,6

The Guardian NG from Edinburgh Sensors

The Guardian NG from Edinburgh Sensors provides near-analyzer quality continuous measurement of CO2 concentrations. This sensor can operate in temperatures of 0-45 °C and relative humidity of 0-95%, and comes with the CO2 detection range of 0 to 3000 ppm.

Guardian NG

Guardian NG

These features make it suitable for use in conditions meant to simulate climate change scenarios. In addition, the Guardian NG can be easily installed as a stand-alone product in greenhouses to measure CO2 levels.4,6

Download the Guardian NG Brochure for More Information


Reduced water availability and increased levels of CO2 are expected in cocoa growing areas by the end of the century as a result of climate change. Researchers studying the potential effects of these conditions on cocoa growth used impact studies to investigate the effects of increased levels of CO2 and reduced water availability on the growth of cocoa plants.

The team observed that water shortages can be alleviated by increased levels of CO2, leading to increased cocoa growth under climate change conditions when compared to present conditions. During their climate change impact studies, the Researchers used gas sensors from Edinburgh Sensors to accurately measure CO2 levels.

References and Further Reading

  1. Lahive F, Hadley P, Daymond AJ, ‘The impact of elevated CO2 and water deficit stress on growth and photosynthesis of juvenile cacao (Theobroma cacao L.)’ Photosynthetica, 2017.
  2. Accessed September 12th, 2017.
  3. Accessed September 12th, 2017.
  4. Accessed September 12th, 2017.
  5. Gornall J, Betts R, Burke E, Clark R, Camp J, Willett K, Wiltshire A ‘Implications of climate change for agricultural productivity in the early twenty-first century‘ Philosophical Transactions B 365(1554):2973-2989, 2010.
  6. Accessed September 12th, 2017.

This information has been sourced, reviewed and adapted from materials provided by Edinburgh Sensors.

For more information on this source, please visit Edinburgh Sensors.


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