Climate Technology & Geoengineering (HL) (DP IB Environmental Systems & Societies (ESS))

Climate Mitigation Technology

• Climate mitigation technology refers to innovations designed to:

  • Reduce greenhouse gas emissions

  • Limit the effects of climate change

• These technologies include:

  • Carbon reduction technologies (decrease carbon emissions from human activities)

  • Carbon removal technologies (capture and store carbon already present in the atmosphere)

Key areas of climate mitigation technology

1. Renewable energy technologies

• Renewable energy sources provide cleaner alternatives to fossil fuels

• They utilise natural resources to produce energy with minimal emissions, e.g.

  • Solar power

  • Wind energy

  • Hydropower

  • Geothermal energy

• Renewable energy technologies are continuously advancing

  • This is making solar, wind, and other renewables more efficient and affordable

  • This is increasing their potential to replace fossil fuels on a large scale

2. Carbon capture and storage (CCS)

• CCS technologies capture carbon dioxide emissions from sources like power plants

  • This carbon is stored underground to prevent release into the atmosphere

  • E.g. Direct air capture (DAC): removes CO₂ directly from the air

3. Energy efficiency technologies

• Energy-efficient technologies aim to reduce energy consumption in buildings, vehicles, and industries

  • Smart buildings: use sensors and AI to manage lighting, heating, and cooling, lowering energy use

  • Electric vehicles (EVs): reduce emissions from traditional petrol and diesel cars

4. Smart cities and digital technologies

• Smart cities integrate technology to improve urban sustainability and reduce emissions

  • Apps and sensors help citizens make eco-friendly choices, e.g. finding nearby charging stations or recycling points

  • Public transportation apps encourage the use of buses, trains, and bikes over personal cars, helping to cut emissions

5. Agriculture and forestry innovations

• Technology in agriculture and forestry can increase carbon sequestration and reduce emissions from land use

  • Precision agriculture: uses sensors and drones to monitor crop health and minimise fertiliser use, reducing nitrous oxide emissions

  • Sustainable forestry: uses science-based methods to grow forests sustainably, increasing their carbon storage potential

Geoengineering

• Geoengineering is a strategy aimed at mitigating climate change by intentionally altering the Earth’s climate systems on a large scale

• Purpose:

  • To treat the symptoms of climate change, not its root causes (such as greenhouse gas emissions)

• Two main types of geoengineering:

  • Solar Radiation Management (SRM): reflects sunlight to cool the Earth

  • Carbon Dioxide Removal (CDR): removes CO₂ from the atmosphere

Types of geoengineering approaches

Solar Radiation Management (SRM)

• Stratospheric aerosol injection:

  • Releases reflective particles (such as sulphates) into the stratosphere

    • This reduces sunlight reaching Earth

• Space mirrors:

  • None currently in operation (there have only been proposals and experiments)

  • Uses large mirrors in space to reflect sunlight away from Earth

  • Highly expensive and technologically complex

    • However, it could theoretically provide global cooling

• Cloud brightening:

  • Sprays sea salt into clouds over oceans, making them brighter and more reflective

  • Intended to reduce ocean surface temperatures

    • E.g. this could help slow coral bleaching

Carbon Dioxide Removal (CDR)

• Ocean fertilisation:

  • Adds nutrients like iron to oceans to boost algae growth

    • Phososynthetic algae absorbs large amounts of CO₂ during photosynthesis

  • Concerns include potential disruption of marine ecosystems and unknown long-term impacts

• Direct Air Capture (DAC):

  • Uses machines to pull CO₂ directly from the air

    • This CO₂ is then stored (e.g. underground) or used

  • Currently high-cost and energy-intensive but is developing as a viable technology

• Bioenergy with Carbon Capture and Storage (BECCS):

  • Combines biomass burning for energy with carbon capture and storage

  • Can effectively create 'negative emissions' by removing CO₂ from the atmosphere

Arguments for Geoengineering

• Rapid cooling potential:

  • SRM methods like stratospheric aerosols could theoretically cool the Earth quickly, helping prevent immediate climate crises

• Backup strategy:

  • Provides an alternative if emissions reduction efforts fail to control warming effectively

• Offsets global warming effects:

  • Reduces extreme heat, potentially slowing down impacts like polar ice melting and sea-level rise

• Innovation in climate action and policy:

  • Stimulates technological advancement and discussion on global climate action strategies

Arguments against Geoengineering

• High uncertainty:

  • Effects on weather patterns, ecosystems, and human health are not fully understood

• Potential for unintended consequences:

  • For example, stratospheric aerosols may alter rainfall patterns, potentially leading to droughts in some regions

• Geopolitical issues:

  • Changes in climate conditions could impact countries differently, leading to conflicts over who controls geoengineering efforts

• Potential to slow genuine climate efforts:

  • May reduce incentives for countries to cut emissions if they believe geoengineering can “solve” climate change

• High costs:

  • Many techniques, like space mirrors and DAC, are currently too expensive to implement on a large scale