The recent ‘Climate Change and Land’ report by the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive look at how climate change pertains to land use. This marks the first time that the IPCC has focused exclusively on the land sector. The report sheds light on how diverse uses of land, such as agriculture, industry, forestry, cattle-rearing, and urbanisation, contribute to the emission of greenhouse gases.
Key Findings: Linking Climate Change and Land Degradation
The report establishes a firm connection between climate change and land degradation. Factors influencing this degradation include temperature fluctuations, changes in precipitation and wind patterns, and shifts in seasonality. For instance, extreme heat events can reduce photosynthesis in trees and slow the growth rate of leaves, therefore affecting the whole tree’s growth. If plants decline in certain regions, land degradation is an expected outcome since vegetation plays a crucial role in preventing erosion. Additionally, increased aridity due to global warming would further exacerbate heat stress, leading to significant deficits in soil moisture and a subsequently higher rate of drying. Changes in rainfall patterns and flooding as a result of climate change may also delay planting, increase soil compaction, and contribute to crop losses.
Land Degradation Defined
The IPCC report defines land degradation as a persistent negative trend in land conditions caused directly or indirectly by human activities, including anthropogenic climate change. This condition is typically expressed as a long-term reduction or loss in biological productivity, ecological integrity, or value to humans. However, the report also notes that some aspects of climate change could potentially improve land conditions, such as CO2 fertilisation, where higher atmospheric CO2 levels stimulate plant growth.
Role of Land in Climate Change
Land acts as both a source and sink of carbon, contributing to climate change. Large-scale land-use changes, such as deforestation, urbanisation, or shifts in cropping patterns, have direct effects on overall greenhouse gas emissions. For instance, land-based activities like agriculture and forestry emit greenhouse gases, making them carbon sources. Conversely, soil, trees, and vegetation absorb carbon dioxide, thereby acting as carbon sinks.
| Carbon Source | Carbon Sink |
|---|---|
| Agriculture, Forestry | Soil, Trees, Vegetation |
Climate Change and Desertification
The IPCC report outlines desertification as a form of land degradation occurring in arid, semi-arid, and dry sub-humid areas, collectively known as drylands, due to various factors including human activities and climatic changes. The risk of desertification is expected to increase due to climate change. Decline in vegetation can result in greater soil erosion risk, enhancing the likelihood of sand and dust storms, which further decrease local precipitation, thus fuelling desertification.
Implications of Land Degradation Driven by Climate Change
The impacts of climate-change-driven land degradation are extensive. The report highlights that climate change often multiplies the risk of both land degradation and poverty. Migration is another outcome, as individuals whose livelihoods are negatively impacted by environmental changes may choose to relocate either within their country or across borders. Climate change also harms food security owing to rising temperatures, altered precipitation patterns, and increased frequency of certain extreme events. This can affect agricultural and livestock production, alter crop nutritional quality, and raise cereal prices, leading to higher food costs and increased risk of food insecurity and hunger.
