Natural changes: Natural Climate Change

Question 1

Overview

Answer 1

Long term change. There are regular cycles (100,000 years) of orbital eccentricity which can cause slight variations in the amount of the Sun’s radiation that warms up the Earth; this causes the Earth to go through natural cycles of glacial periods and warm periods

A recent rise in CO2 has now surpassed 400 ppm. The trend for temperature and CO2 indicates that high temperatures are associated with higher levels of CO2.

Question 2

Quaternary period

Answer 2

during the Quaternary period (from 2.6 million years ago to the present day) carbon levels have fluctuated. Levels of carbon reached as low as 180 ppm (parts per million). The average interglacial atmosphere carbon content is 280 ppm of carbon. This was 300 ppm at the start of the Industrial Revolution

affected by cold glacial periods

Question 3

Colder vs warmer climates

Answer 3

❄️ more chemical weathering as cold water can hold more co2
🌡Melting of permafrost in. tundra regions

❄️Decomposers are less effective so carbon transfer to soil reduced
🌡More effective

❄️More water is locked up as snow/ice so less water flow to oceans, less sediment transfer
🌡Opposite

Question 4

Colder vs warmer climates

Answer 4

❄️Restricted plant growth, reducing co2 release from vegetation
🌡Increased plant growth, increasing co2 release

❄️cooler oceans restrict marine biology reducing co2 absorption for photosynthesis
🌡warmer oceans have more marine biology