IB Diploma Environmental Systems & Societies HL · Climate Change and Energy Production
Mini-Lesson
Climate Change and Energy
This mini-lesson tackles the defining environmental issue of our time: the natural and enhanced greenhouse effect, the gases that drive it and their global warming potential, the evidence, feedbacks and impacts of climate change, the difference between mitigation and adaptation, and the energy choices — fossil, renewable and nuclear — that will decide our future emissions.
Perspectives lens: climate change is a global commons problem — emissions anywhere warm everywhere, so it demands international cooperation and raises hard questions of fairness between rich and poor nations.
Work through each screen, answer the questions as you go (some are wordy, some are calculations) and collect ⭐ stars. Press Start when you're ready.
Climate · the greenhouse effect
The natural and enhanced greenhouse effect
The natural greenhouse effect keeps Earth about 33°C warmer than it would otherwise be, making life possible. Greenhouse gases let in short-wave solar radiation but absorb and re-emit the long-wave (infrared) heat radiated back from the surface, trapping warmth.
The enhanced greenhouse effect is the extra warming caused by human additions of greenhouse gases — chiefly from burning fossil fuels, deforestation and agriculture — raising global temperatures beyond the natural balance.
Quick check
How warming works
?How do greenhouse gases warm the planet?
Climate · the gases
Greenhouse gases and global warming potential
Not all greenhouse gases are equal. Global warming potential (GWP) compares how much heat a gas traps relative to CO₂ over a set period.
Carbon dioxide (CO₂) — GWP = 1 (the baseline); from combustion and deforestation; huge quantities.
Methane (CH₄) — GWP ≈ 28× CO₂; from livestock, rice paddies, landfill and gas leaks.
Nitrous oxide (N₂O) — GWP ≈ 265× CO₂; from fertilisers.
Halocarbons — very high GWP but small amounts.
Calculate
Your turn — CO₂ equivalent
1Methane has a global warming potential about 28 times that of CO₂. Calculate the CO₂-equivalent warming of 5 tonnes of methane.
t CO₂e
Hint: CO₂e = mass × GWP = 5 × 28.
Quick check
Tonne for tonne
?Why is a tonne of methane a bigger climate concern than a tonne of carbon dioxide?
Climate · evidence and feedback
Evidence and feedback loops
Evidence for climate change includes rising global mean temperature, shrinking ice sheets and glaciers, rising sea levels, ocean acidification and ice-core records linking CO₂ to temperature.
Positive feedbacks amplify the warming:
Ice–albedo: melting ice exposes dark water/land, absorbing more heat, causing more melting.
Permafrost methane: thawing tundra releases methane, which warms further.
Water vapour: warmer air holds more vapour, itself a greenhouse gas.
Quick check
A dangerous loop
?Melting Arctic sea ice exposes dark ocean, which absorbs more sunlight, warming the water and melting more ice. What kind of feedback is this?
Climate · impacts
Impacts of a warming world
Sea-level rise from thermal expansion and melting ice threatens low-lying nations and coastal cities.
Ecosystem shifts — species move poleward or upslope; coral bleaching; mismatched food chains.
Extreme weather — more intense heatwaves, droughts, storms and floods.
Human impacts — threats to food and water security, health, and climate-driven migration.
Climate · responses
Mitigation vs adaptation
Mitigation — tackling the causes to reduce the extent of climate change: switching to renewables, energy efficiency, reforestation, carbon capture, cutting methane.
Adaptation — adjusting to the effects we cannot avoid: sea walls and flood defences, drought-resistant crops, early-warning systems, water storage.
A sound strategy needs both — but mitigation is a shared global duty, while adaptation often falls hardest on the poorest, least-responsible nations.
Match it
Match the climate terms
Tap a statement on the left, then its matching answer on the right.
Statement
Answer
Energy · the choices
Comparing energy sources
Energy security means reliable, affordable access to energy. Sources trade off cost, reliability and environmental impact:
Fossil fuels (coal, oil, gas) — energy-dense and reliable, but finite and the main source of CO₂.
Renewables (solar, wind, hydro, geothermal, tidal, biomass) — low-carbon and replenishing, but often intermittent or site-specific.
Nuclear — low-carbon and reliable, but produces long-lived radioactive waste and carries accident risk.
Energy choices are shaped by value systems: technocentrics favour nuclear and carbon capture; ecocentrics favour renewables and using less.
Sort it
Sort the energy sources
Tap a source, then tap the category it belongs to.
♻️ Renewable
🛢️ Fossil fuel
☢️ Nuclear
Calculate
Your turn — the renewable share
2A country generates 400 TWh of electricity a year, of which 100 TWh comes from renewables. Calculate the percentage of electricity from renewable sources.
%
Hint: (100 ÷ 400) × 100.
Calculate
Your turn — power-station efficiency
3A coal power station consumes fuel at a rate of 1000 MW but delivers only 380 MW of electricity. Calculate its energy efficiency.
Because emissions cross all borders, treaties try to coordinate action:
Kyoto Protocol (1997) — first binding targets, but only for developed nations, and the biggest emitters did not all commit.
Paris Agreement (2015) — nearly all nations pledge to hold warming "well below 2°C" (aiming for 1.5°C) via their own nationally determined contributions.
The challenge: pledges are voluntary and current commitments still fall short of the 1.5°C goal — a classic tragedy of the commons.
Quick check
Mitigation or adaptation?
?A coastal city builds higher sea walls and flood barriers to cope with rising seas. Is this mitigation or adaptation?