3.1.1.4 Water, carbon, climate and life on Earth

Carbon cycle role in supporting life

Fundamental building block of life as it forms carbs, proteins, fats and DNA. Mainly in soil and food chains

Carbon cycle role in food chains

Carbon is fixed into biomass through photosynthesis forming the base of all food chains

Carbon cycle role in soil and productivity

Carbon in soils support soil fertility, microbial activity and agricultural productivity

What does the water cycle influence

Organisms, ecosystem/climate

Water cycle role in organisms

Essential for photosynthesis, nutrient transport and thermoregulation

Water cycle role in ecosystems and climate

Regulates freshwater availability, soil moisture and ecosystem distribution. Controls heat distribution and precipitation

What is the shared role of the carbon and water cycles

Regulate climate to make Earth habitable

Photosynthesis in water x carbon relationship

High rates of photosynthesis and transpiration in carbon sinks create humidity/cloud cover for rainfall

Evapotranspiration in water x carbon relationship

Rising co2 warming closes plant pores earlier, influencing atmospheric moisture/cloud formation which goes on to decrease forest storage due to thermal stress

Water vapour in water x carbon relationship

Amplifies warming caused by co2 in the atmosphere

Transfers humans can intervene in

Combustion, photosynthesis, land use change

Human intervention in combustion

Renewable energy reduces rate of carbon transfer to atmosphere. CCS in Boundary Dam is first commercial carbon capture plant

Human intervention in photosynthesis (positive)

Afforestation and reforestation increases carbon uptake

Human intervention in land use change

Sustainable farming practice such as carbon farming (growing legumes and minimised soil disturbance) increase transfer into soil stores

Tropical regional impacts of carbon cycle

Temperatures increase respiration/decomposition which reduce net carbon storage

Feedback link to climate change

Anthropogenic emissions could reach a ‘tipping point’ of endless positive cycles,’dieback’ in the amazon where it can no longer support own rainfall

Implications of climate change for life on earth

Marine ecosystems damaged by acidification, reduced freshwater availability, biological productivity

High latitude regional impacts of carbon cycle

Temperatures melt permafrost to release co2 and reduce albedo

Paris Agreement 2015 - Bottom down

Legally binding agreements to limit global warming to well below 2C by reducing greenhouse gas emissions and enhancing carbon sinks. Countries submits Nationally Determined Contributions every 5 years to promote mitigation and adaption. Effectiveness is limited by voluntary targets and uneven compliance.

Kyoto Protocol (1997) - Top down

First legally binding treaty where nations pledge to cut emission by 5% by 2012. ‘Cap and trade’ system where countries could sell spare ‘carbon credits’ to exceeding countries. Major polluters like China/India exempt due to NEEs, causing America to not sign and industry moving to NEEs.