• Human activities increase atmospheric CO₂, methane, and other greenhouse gases
• Fossil fuels, cement, agriculture, deforestation, and land-use change are major sources
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
2
Learning objective
D4.3.2—Positive feedback cycles
New
• Positive feedback amplifies warming after an initial climate change
• Examples include ice-albedo loss, permafrost methane, ocean CO₂ release, and wildfire feedback
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
3
Learning objective
D4.3.3—Boreal forest tipping point
New
• Boreal forests can shift from carbon sinks to carbon sources
• Warming, drought, reduced snowfall, browning, insects, and fire increase tipping-point risk
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
4
Learning objective
D4.3.4—Polar habitat changes
New
• Melting landfast ice and sea ice alters breeding, feeding, and resting habitat
• Emperor penguins and walruses illustrate species dependent on ice timing and extent
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
5
Learning objective
D4.3.5—Ocean current changes
New
• Ocean warming strengthens stratification and can reduce nutrient upwelling
• Reduced upwelling lowers phytoplankton productivity and food supply
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
6
Learning objective
D4.3.6—Range shifts
New
• Species ranges can shift poleward, upslope, or contract as climate zones move
• Montane birds and North American tree species show changing distribution limits
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
7
Learning objective
D4.3.7—Coral reef threats
New
• Warming causes coral bleaching by disrupting coral-zooxanthellae mutualism
• Ocean acidification suppresses calcification, threatening reef biodiversity and collapse
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
8
Learning objective
D4.3.8—Carbon sequestration approaches
New
• Carbon sequestration captures and stores atmospheric carbon dioxide
• Afforestation, agroforestry, forest regeneration, and peatland rewetting increase carbon stores
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
9
Learning objective
D4.3.9 (HL)—Phenology
New
• Phenology studies timing of seasonal biological events
• Events include flowering, budburst, migration, nesting, breeding, and insect emergence
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
10
Learning objective
D4.3.10 (HL)—Disruption of phenological synchrony
New
• Climate change can desynchronize interacting species that rely on matched timing
• Arctic plant-reindeer migration and great tit-caterpillar peaks are key examples
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
11
Learning objective
D4.3.11 (HL)—Increased insect life cycles
New
• Warmer temperatures can shorten insect development and add generations per year
• Spruce bark beetles can shift from one to two annual attack periods
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.
12
Learning objective
D4.3.12 (HL)—Evolution from climate change
New
• Climate change alters selection pressures and can shift phenotype frequencies
• Finnish tawny owl colour change links milder winters, snow cover, and survival
0%
Mastery
0
Attempts
0
Mistakes
Start with the concept explanation, then practise to create mastery evidence.