Climate change and global warming

Introduction

The 13th of the Sustainable Development Goals (SDGs) addresses climate.

Several gases in the atmosphere trap energy from the sun – and warm the earth. Without this “greenhouse effect” life would not be possible on this planet. Our activities over the past two centuries though, especially the burning of fossil fuels like coal and oil, have increased the building up of greenhouse gases in the atmosphere. More energy from the sun is being trapped and the earth is becoming warmer. “Global warming” refers to this enhanced greenhouse effect.

It is true that our planet goes through natural cycles of change, lasting hundreds of years. In that amount of time, though, plants and animals are able to adapt. The manner in which humanity is developing though has speeded up the changes in climate, leaving less time to adapt and placing our ecosystems in danger.

And so we are seeing more intense rainstorms, a decrease in rainfall frequency, droughts of higher intensity, greater rainwater runoff and thus soil erosion (Du Pisani 2020). These changes present serious challenges to agriculture and forestry, and to the societies and economies that depend on these sectors for food, fibre and livelihoods.

The mainstream climate change/global warming is disputed by a significant minority of scientists. Interested readers can visit http://ecosense.me, or Google Dr Patrick Moore and others and see where the trail leads …

Causes and Effects of Climate Change (National Geographic, 2017), a three-minute video summary

Mitigation: what can we do to slow the process down?

Mitigation entails all human interventions that reduce the sources or enhance the sinks of greenhouse gases.

The enhanced greenhouse effect can be slowed down by following two guidelines:

  • increase sinks
  • decrease sources of greenhouse gases

A sink is a process which removes greenhouse gases from the atmosphere. For example: growing a tree where one did not previously exist provides a sink for carbon dioxide, because the tree “extracts” carbon dioxide for photosynthesis.

The energy sector is the largest single source of greenhouse gases in South Africa. Integrated energy planning at the national level should ensure the optimum overall mix of energy sources, with clean coal technologies expected to be part of such a mix for the medium-term future.

Climate Change and South African agriculture: impacts and adaption options

A chapter in the Bureau for Food & Agricultural Policy (BFAP) Baseline 2022-2031 was termed “Climate change impacts: Mitigation and adaption requirements for the South African agricultural sector”. 

Farmers report having used the following strategies to cope with climate change:

(a) Adjustments in farming operations

  • Changes have been made in the planting dates of some crops.
  • Crops with a shorter growing period such as cabbage have been planted, as well as short season maize (120 days – 140 days).
  • There has been an increased use of crop rotation and the early harvesting of some crops. In KwaZulu-Natal for example, farmers prefer to cut their sugarcane at an early stage to avoid the loss of production due to the dryness of the cane (as a result of increased temperature) if they have to wait for the cane to mature in the field.

In the situation of heavier rainfall, concentrated in shorter periods and starting earlier (previously early September and now late October in some provinces), farmers have responded by-

  • delaying the start of the planting period;
  • the increased use of modern machinery to take advantage of the shorter planting period;
  • the collection of rain water by making furrows near the plants; and
  • the increased use of irrigation.

In response to higher temperatures, farmers have resorted to using

  • heat tolerant crop varieties;
  • crop varieties with high water use efficiency;
  • early maturing crop varieties, and increased crop and livestock farming (mixed farming). For example, because of the high temperatures, sugarcane farmers have shifted to producing macadamia nuts and tea, which they consider easier to irrigate than sugarcane.

Livestock farmers have also adopted numerous practices aimed at efficient use of water and scarce fodder. There is a general tendency to resort to more heat tolerant breeds rather than the traditional ones, and most livestock farmers now also produce their own fodder, such as lucerne or maize, and stock it for use during the long dry seasons. In response to the long drought periods, farmers have adjusted the stocking intensity of their livestock by selling their animals at younger ages. Another practice is to change the timing, duration and location of grazing.

(b) Increased chemical application

  • With higher temperature and increased evapotranspiration, farmers have resorted to increased application of chemicals such as Erian to slow down evapotranspiration.
  • They also apply more farm manure to keep the moisture content of the soil higher and retain the soil fertility.
  • More lime is also applied to maintain the soil’s correct pH balance.

(c) Increased use of irrigation

  • With water being the most important factor limiting agriculture in South Africa, irrigation appears to be the most appropriate adaptive strategy. Hence 65% of the respondents choose irrigation as an option to adjust to climatic changes.
  • Farmers have also shifted from flood irrigation to sprinkler irrigation for an efficient use of the limited water.
  • Several farms have also built their own boreholes to make effective use of underground water.
  • There has also been increased use of wetlands for agricultural production.

(d) Shade and shelter

  • When it is hot, livestock farmers plant trees to provide natural shades for their livestock or as a wind or hail storm break. In South Africa, farmers generally plant pine trees and Acacia karoo and Celtis africana trees for this purpose.
  • In some instances, farmers use fishnets, grass, and plastics as coverings to protect their plants against dryness and heat, and cold and frost.
  • Heating provided by firewood and paraffin heaters is also used by livestock farmers to protect their animals against the cold.

(e) Conservation practices

  • In response to the increased occurrence of droughts farmers have adopted various soil conservation practices in order to maintain or improve soil moisture and fertility.
  • Principally to fight erosion, farmers have built many small dams or planted trees around their farms.
  • Farmers have also increased their fallow periods by as much as one to two agricultural seasons (instead of continuous cropping), to allow the land to restore its nutrients.
  • Another conservation technique farmers use to protect the soil against erosion is to keep the crop residues of the previous harvest on the land. To preserve soil moisture, cool the soil surface and stabilise soil temperature, they used mulching (layers of muck, peat, compost and plastics) to cover the land.
  • To avoid excessive extraction of nutrients in the soil of their farms, farmers have also reduced the density of crops or livestock on their land.

(f) Other practices

  • To reduce the risk of losing income when farm produce decreases as a result of the increased variability in the climate, some (especially large-scale farmers) have insured their farms, while others (especially small-scale farmers) are increasing their involvement in non-farm activities.
  • Most large-scale farmers have also opted to taking lower risks by reducing their cropping areas to manageable sizes.
Source: adapted from the paper Climate Change and South African Agriculture: Impacts and Adaptation Options by James KA Benhin

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The percentage of Agriculture’s contribution to climate change is disputed, and ranges from 22% down to somewhere between 10% and 5%. The largest portion of this is attributed to livestock (but see the note on the Savory Institute under the “International business environment” heading).

Research shows that agriculture has a huge potential to cost-effectively reduce greenhouse gases through changes in agricultural technologies and management practices, particularly in developed countries. Climate-smart agriculture includes proven practical techniques including mulching, intercropping, conservation agriculture, crop rotation, integrated crop-livestock management, agro-forestry, improved grazing and improved water management.

Climate changes create risks and uncertainty with potentially serious downsides. Without strong adaptation measures, climate change could reduce food crop production by 10 to 20 percent by the 2050s, with more severe losses in Africa. With nine billion people expected to inhabit the world by 2050, food production in Africa alone must be tripled, according to experts.

National strategy and government contact

South Africa’s commitment to climate change interventions is guided by the United Nations Framework Convention on Climate Change, the Millennium Declaration and the Paris Climate Agreement.

South Africa’s Just Energy Transition Partnership (JETP) was announced at COP26 (2021), and $8.5-billion (R128-billion) in concessional climate financing offered from various developed countries (COP27, 2022). The JETP is an international partnership to help South Africa move away from its dependence on coal.

The Climate Change Act (passed into law in July 2024) “seeks to provide for a just transition away from South Africa’s current carbon-intensive energy system and towards a decarbonised economy and society, while meeting the country’s critical development challenges”. South Africa’s response to climate change had previously been governed by the National Climate Change Response White Paper (approved by Cabinet in 2011), and the National Climate Change Adaptation Strategy (NCCAS) (approved in 2020).

GOVERNMENT ROLE PLAYERS

Presidential Climate Commission www.climatecommission.org.za

Department of Forestry, Fisheries and the Environment (DFFE) www.dffe.gov.za

Department of Trade, Industry and Competition (the dtic) www.thedtic.gov.za

Department of Agriculture, Land Reform and Rural Development (DALRRD) Directorate: Climate Change and Disaster Management www.dalrrd.gov.za  

Department of Cooperative Governance and Traditional Affairs South African National Disaster Management Centre www.ndmc.gov.za

Department of Mineral Resources and Energy (DMRE) www.energy.gov.za

  • South Africa’s is a coal-based economy, and as such ranks amongst the highest emitters of greenhouse gases in the world. It needs to explore clean energy initiatives, manage demand, and move towards a low-carbon economy. Read about the various projects and programmes on the website.
  • The Clean Development Mechanism (CDM) is one of the two project-based flexible mechanisms of the Kyoto Protocol. Under the rules of the CDM, each host country must establish a Designated National Authority (DNA). The DNA for the CDM in South Africa is located in the DMRE. Find the “Designated National Authority” option on the website.
  • South African Carbon Offset Administration System (COAS) https://carbon.energy.gov.za

National Treasury www.treasury.gov.za

  • Find the Carbon Tax Bill on the website.

Department of Water & Sanitation www.dws.gov.za

Role players

Further reference:

  • Nedbank, in partnership with the Sustainability Institute (Stellenbosch University) launched Carbon footprinting: A practical calculation guide focusing on measuring, monitoring, reporting and verification. Find the free publication on the Internet.
  • Read about the Smart Agriculture for Climate Resilience (SmartAgri) project at www.greenagri.org.za (find “SmartAgri” option). It is a collaboration between the Western Cape Department of Agriculture (DOA) and the Western Cape Department of Environmental Affairs & Development Planning (DEA&DP), and the University of Cape Town’s African Climate and Development Initiative (ACDI)

International business environment

Websites and publications

Some articles:

Agriculture and climate change

Climate change – general