Monitoring & Predicting Climate Change (Cambridge (CIE) AS Environmental Management)

Monitoring & Predicting Climate Change

• The ability to monitor and predict climate change is important in order for us to understand the complex dynamics of Earth's climate system and anticipate future changes:

  • Scientists use various observational techniques, data sources and computational models to monitor past climate trends and forecast future climate scenarios

Difficulties in Monitoring and Predicting Climate Change

• Limited historical data:

  • Reconstruction of past climate conditions relies on sparse historical records, which can sometimes lack detail, such as ice cores, sediment layers and tree rings:

    • For example, ice core analysis from Antarctica provides insights into atmospheric composition and temperature variations over millennia

  • However, these records may not always capture detailed regional climate variability or extreme events

• Complex climate models:

  • Future climate projections rely on sophisticated computer models that simulate interactions between the atmosphere, oceans, land surfaces and ice

  • However, these models always have uncertainties as they attempt to replicate highly complex Earth system processes:

    • For example, climate models struggle to accurately simulate the behaviour of clouds, which play a crucial role in regulating Earth's energy balance and global temperatures

• Uncertainty in feedback mechanisms:

  • Climate feedback mechanisms, such as the albedo effect and carbon cycle feedbacks, introduce complexities and uncertainties into climate predictions:

    • For example, melting Arctic sea ice reduces the Earth's albedo, leading to increased absorption of solar radiation and further warming

  • These feedback loops are challenging to model accurately and may lead to unpredictable climate responses

• Time delays:

  • There is a lag between the emission of greenhouse gases and their impacts on the climate system:

    • For example, carbon dioxide emissions from fossil fuel combustion can persist in the atmosphere for centuries, contributing to long-term climate change

    • However, we are only just now starting to feel the full effects of centuries of carbon dioxide emission from fossil fuel combustion (i.e. since the start of the industrial revolution)

  • Predicting the timing and magnitude of future climate impacts requires careful accounting for these time delays

• Data uncertainty and interpretation:

  • Climate research relies on diverse datasets from various sources, including satellite observations, ground-based measurements and paleoclimate proxies

  • Discrepancies in data quality, measurement techniques and interpretation methods can lead to uncertainties in climate predictions:

    • For example, disagreement over temperature reconstructions from tree ring data has caused debates about historical climate variability

Modelling Future Climate Change

• It is possible to use existing data relating to global warming to make predictions about global temperatures in the future:

  • Using data in this way is known as extrapolating from data

  • Extrapolated data can be used to produce models that show how the climate may change in the future

• Global warming predictions can be used to:

  • Plan for the future, for example:

    • Building flood defences

    • Funding scientific research into climate change technologies

  • Encourage people to change their activities, for example:

    • Reduce the burning of fossil fuels

    • Increase the use of renewable energy sources such as solar and wind energy

    • Reduce meat consumption

• The Intergovernmental Panel on Climate Change, or IPCC, is a group of climate scientists around the world that has used existing data to extrapolate how global temperatures might change in the future under different human activity scenarios, for example:

  • If humans manage to immediately begin reducing fossil fuel use, global temperature change could be limited to around 1 - 1.5 °C

  • If humans do nothing to change their fossil fuel use, global temperature increase may exceed 4°C

• The IPCC data can be added to other computer models on climate change to see how different parts of the world might be affected under the different scenarios

• There are limitations to models based on extrapolated data:

  • The IPCC has produced models based on several emissions scenarios, and we do not know which of these scenarios is most likely:

    • I.e. we don't know how successful humans will be at cutting greenhouse gas emissions

  • We do not know whether future technologies will be successful at removing greenhouse gases from the atmosphere e.g. carbon capture technologies may or may not be effective 

  • It is unknown exactly how atmospheric gas concentrations might affect global temperatures

  • Global climate patterns are complex and therefore predictions are difficult:

    • It is possible that a certain tipping point in global temperatures could lead to a sudden acceleration in global warming e.g. permafrost melting may cause a sudden increase in atmospheric methane

  • We don't know exactly how factors other than human activities may affect climate in the future e.g. a volcanic eruption could increase ash in the atmosphere, reflecting radiation back into space and cooling the earth