Positive & Negative Impacts of Climate Change (SL IB Environmental Systems & Societies (ESS))

• Climate change is a global phenomenon, but its impacts can vary significantly from one location to another
• There are many potential impacts of climate change, some of which can be perceived as either adverse or beneficial:

Changes in Water Availability

• • Climate change can lead to alterations in precipitation patterns, resulting in changes in water availability
  • Some regions may experience increased rainfall and flooding, while others may face more frequent and severe droughts, impacting water resources for agriculture, drinking water, and ecosystems

Distribution of Biomes and Crop Growing Areas

• • As temperatures and precipitation patterns shift, the distribution of biomes and suitable areas for agriculture can change
  • Some regions may experience expansion of favourable conditions for crops and ecosystems, while others may face the loss or shifting of suitable habitats, impacting food production and biodiversity

Loss of Biodiversity and Ecosystem Services

• • Climate change can disrupt ecosystems, leading to the loss of biodiversity and the services they provide
  • Changes in temperature, rainfall, and habitats can affect species' survival, migration patterns, and interactions, resulting in shifts in ecosystem functioning and potential declines in ecosystem services

Coastal Flooding

• • Rising sea levels, attributed to climate change, can lead to coastal flooding and increased vulnerability to storm surges
  • This can result in the loss of land, infrastructure, and displacement of coastal communities

Ocean Acidification

• • Increasing levels of carbon dioxide in the atmosphere lead to the absorption of more carbon dioxide by the oceans, resulting in ocean acidification
  • This can have detrimental effects on marine life, including coral reefs, shellfish, and other organisms that rely on calcium carbonate for their shells and skeletons

Damage to Human Health

• • Climate change can impact human health in various ways
  • Heatwaves, extreme weather events, changes in disease vectors (e.g. mosquitos), and reduced air quality can all have negative health consequences, including heat-related illnesses, respiratory problems, and the spread of infectious diseases

Coastal flooding is becoming increasingly common as a consequence of the rising sea levels caused by global warming

• It's important to note that while some regions may experience certain benefits from climate change, such as increased agricultural productivity or longer growing seasons, the overall negative impacts tend to outweigh the positive ones
• Adapting to and mitigating climate change is crucial to minimise the potential adverse effects and protect ecosystems, biodiversity, human well-being, and the overall stability of the planet

Negative and Positive Feedback Mechanisms

• Both negative and positive feedback mechanisms are associated with climate change and may involve very long time lags

• Negative feedback mechanisms in climate change refer to processes that counteract or reverse the initial change, helping to stabilise the climate system
  • For example, as temperatures increase, the enhanced evaporation may lead to increased cloud cover, which can reflect more sunlight back into space, thus cooling the Earth's surface
  • Another negative feedback mechanism involves the absorption of carbon dioxide by oceans and vegetation, which helps regulate its concentration in the atmosphere

• Positive feedback mechanisms in climate change amplify or intensify the initial change, leading to further global warming
  • For example, as temperatures rise, the melting of ice caps and glaciers reduces the Earth's albedo, causing more sunlight to be absorbed and increasing warming
  • Another positive feedback mechanism involves the release of methane from thawing permafrost, which further enhances the greenhouse effect

• Time lags refer to the delay between a cause and its effect in the climate system, which can span decades or even centuries
  • For example, the release of carbon dioxide from burning fossil fuels may have immediate warming effects, but the full impact on global temperatures may take years to manifest due to thermal inertia in the oceans (the slow speed at which oceans actually warm up) and slow feedback processes
  • Similarly, changes in land use, such as deforestation, can have long-term consequences for climate as it takes time for ecosystems to respond and feedback to develop

• These feedback mechanisms and time lags make the climate system complex and challenging to predict accurately, contributing to uncertainties in climate projections
• Understanding and quantifying these feedback mechanisms and time lags is crucial for accurately assessing the potential impacts of climate change and developing effective mitigation and adaptation strategies