Planetary Warming Risks Carbon Release, Requiring Multi-Level Responses

Future Trends

There are significant future uncertainties in regard to climate warming rates, atmospheric conditions, emission levels and carbon concentrations due to:

• Natural Factors Even if GHG emissions stopped, would take a long time for natural systems to restore to pre-industrialisation levels

Terrestrial Sinks	Ocean Sink
Projected to ↑ generally until 2050, but then when saturation is reached they will begin to act as sources: ● Thawing tundra permafrost in the Arctic ● Shift of boreal forests to the N as tundra thaws ● Tropical rainforests already at their C capacity and may ↓ their storage, especially post drought	Increased store in sea grasses & algae, but overall ↓ in sink because… ● Tropical oceans have decreased CO2 solubility because they are warming, ∴ less CO2 uptake ● Decreased efficiency and slowing down of the biological pump taking nutrients and dissolved inorganic carbon from the surface to ocean floor sediment sink

Human Factors

• Economic→ More developed countries have emerged economically w/in last 30 yrs, ∴ ↑ in energy use and emissions (eg. China). Many other countries still to develop ∴ may worsen situation. ↳ Temp reductions in emissions due to recessions, pandemics etc have been seen

• Population→ More people w/ higher levels of wealth use more energy and ↑ in globalisation = more travel & transportation of goods ∴ more emissions. Also many cultural, lifestyle and ideologies have changed recently significant drive towards consumerism But, education makes people more aware of impacts as a result of their consumption (Kuznets Curve) which can ∴ lower emissions levels. May encourage tech advancements which can ↑ energy efficiency

• Energy Sources→ Global agreements (eg. Paris, 2016) make countries review their energy mixes. Has encouraged ↑ use of renewable technologies

Feedback Mechanisms

Feedback occurs when an output change is redirected back to an input

↳ A positive feedback mechanisms amplifies the original process, while a negative one dampens it. Changes to the following lead to feedback into climate change

• Carbon from Peatlands and Permafrost As temps ↑, Boreal & Tundra biomes and climate areas will shift N. Warming causes Boreal peatlands to release carbon in the form of methane as they dry and decayed organic material frozen within Tundra permafrost melts and releases stored gases into the atmosphere. These organic layers are also a large carbon store and they decompose faster in a warmer climate, thereby releasing more CO2 into the atmosphere.

∴, changes to peatlands and permafrost caused by climate change release more gas to the atmosphere, increasing GHG concentration which traps more heat energy and raises temperatures further, leading to further drying/melting.

• Forest Dieback Rainfall in Tropical rainforests is largely recycled, so drought may cause trees to die and areas to adapt to the drier conditions by becoming less productive grasslands, ∴ less CO2 will be absorbed from the atmosphere & warming will ↑, causing further dieback. A tipping point could be reached when moisture can no longer be recycled (due to lack of trees to intake moisture) causing more trees to die. Water stress in boreal forests due to hot dry Summers can result in tree loss. A tipping point could be reached when trees no longer absorb much CO2, which increases GHG concentration in the atmosphere, leading to further dry Summers.

Drought stress in Boreal forests - with more disease, pests and wildfires - could change it to grassland and shrubs.

Weather has a direct influence on vegetation productivity and the rate of chemical reactions, but future vegetation changes are uncertain as it is unknown how climates will change.

• Changes in Thermohaline Circulation More freshwater (for example, from melting of the Greenland ice sheet) changes seawater density, altering ocean currents. Eg. in the North Atlantic, this may cause the Gulf Stream not to flow as far N. Such circulation changes could alter how the oceans and atmosphere transfer heat energy, causing greater warming and more ice melt.

Tipping Point → This is a critical threshold, where any small changes in the global climate system beyond it can transform a stable system irreversibly

Adaptation Strategies

Adaptation → Living with the problem as opposed to solving it. Involves changing ways of living in such a way that enables us to cope with most - if not all - the outcomes of global warming.

Adaptation strategy	Benefits	Costs & risks
Water Conservation & Management	● Less resources used, less groundwater abstraction ● Attitudinal change operates on a long-term basis: Use more grey water ● Low cost technologies available	● Efficiency and conservation cannot match ↑ in demands for water ● Changing cultural habits of a large water footprint needs promotion & enforcement by govs (eg. smart metres) ● Expensive large scale schemes may be required to transfer water in drought-prone areas ● Disputes can also arise over water in transboundary drainage basins such as the Nile
Resilient Agricultural Systems	● Higher-tech drought tolerant species heko resistance to climate change & increased diseases ● Low-tech measures & better practices generate healthier soils and may help CO2 sequestration and water storage: Selective irrigation, mulching, cover crops, crop rotation, reduced ploughing, agroforestry ● More indoor intensive farming	● More expensive tech, seeds and breeds unavailable to poor subsistence farmers w/out aid ● High energy costs from indoor & intensive farming ● Genetic modification is still debated ● Growing food insecurity in many places adds pressure to find quick fixes ● Diversification must be targeted and backed by policy makers, markets and farmers if it is to be successful
Land-use Planning	● Soft management: Land-use zoning, building restrictions in vulnerable flood plains and low-lying coasts ● Enforcing strict run-off controls and soakaways ● Building regs can stipulate structures are built to withstand severe storms etc	● Public opposition ● Abandoning high-risk areas and land-use resettling is often unfeasible, and in megacities such as Dhaka, Mumbai etc ● High costs to move existing land uses due to existing ownership ● Politically fragile ● Needs strong governance, enforcement & compensation
Flood Risk Management	● Hard management traditionally used (localised flood defences, river dredging) ● Simple changes can ↓ flood risk eg. permeable tarmac ● Mangroves can be planted in coastal areas to impeded storm surges ● Reduced deforestation and more afforestation upstream to absorb water and reduce downstream flood risk ● Structures can be adapted in high risk areas, eg. raising buildings	● Debate over funding sources ● Landowners may demand compensation for afforestation or 'sacrificial purposes' ● Constant maintenance is needed in hard management ● Engrained culture of developing techno-centric solutions limits thinking surrounding softer management schemes which may be more effective (working with natural processes instead of trying to overcome them)

	Above Predicted Flood Levels
Solar Radiation Management	● Geoengineering involves ideas and plans to deliberately intervene in the climate system to counteract global warming ● The proposal is to use orbiting satellites to deflect some inward radiation back into space ● It could cool the earth w/in months & relatively cheap compared w/ mitigation	● Untried & untested ● Would ↓ but not eliminate the worst effects of GHGs (eg. would not alter acidification) ● Involves altering a v complex system, which may have unintended consequences ● Requires high inputs of capital, so can only be contemplated by wealthy nations ● Finally, if SRM stopped suddenly there would be a rapid adjustment of the climate system, so geoengineering would have to continue indefinitely to avoid this

Mitigation Strategies

Mitigation → Tackling the root cause of the problem. Reducing or preventing GHG emissions by devising new technologies and adopting low-carbon energies (renewables and recyclables)

The long term solution to global warming is rebalancing the carbon cycle, in particular by reducing GHG concentration in the atmosphere. Can be achieved through mitigation, but schemes necessitate global agreement and national actions (ie. player integration). Successful implementation also requires societal change of thoughts & actions. Gov departments are responsible for mitigation policies - eg. in the UK, Department of Energy and Climate Change (DECC) has a policy to move to low carbon DECC policies

Method	Policy
Carbon Taxation	● Can be an effective way of mitigating climate change, because the extra costs for people and businesses make them consider moving to low-carbon alternatives in order to avoid them • for example, people switching to electric cars which reduce carbon emissions ● The Kyoto protocol and Paris agreement brought widespread international action on reduction targets, with governments introducing laws to bring change within their countries - However, low-carbon technologies are often initially more expensive so not everyone is willing or able to make such investments. Businesses may also pass on additional costs to consumers. ● Carbon price floor tax sets a minimum price companies have to pay to emit CO2 ● Unpopular w/ both industry & environmental groups and has debatable effect on emissions ○ 2015 • The policy was frozen ○ But gas & oil exploration tax relief was expanded to support fossil fuels
Renewable Switching	● Moving from use of fossil fuels to renewables, especially for electricity generation, greatly reduces carbon emissions ● Renewable technologies are more widespread in developed and emerging economies, but not always available in developing nations ● The relationship between big energy producers and the government dictates the amount of switching from fossil fuels to renewables and nuclear power. ○ Renewables provide intermittent electricity, whilst current infrastructure requires continuous power which only fossil fuels provide, so it will take a long time for renewables to be the main source of primary energy ● The Climate Change Levy, designed in 2001 to encourage renewable energy investment and use, was cut in 2015
Energy Efficiency	● Government regulations such as EU directives have forced manufacturers to make more energy efficient goods. Lifestyle changes can reduce energy use, so the biggest savings for this mitigation measure can be made in developed nations where people are more aware of environmental impacts ● In the UK, a Green Deal scheme was used to encourage energy-saving home improvements eg. grants for improving insulation (this was scrapped in 2015) ● Energy suppliers also have to comply with regulations to deliver energy-efficient measures to households.

Afforestation

● Planting more forests would increase storage and reduce atmospheric concentrations - However, many countries are deforesting for commercial or subsistence purposes • especially emerging and tropical developing countries ● In the UK, tree planting is increasing, which helps carbon sequestration. - Involves the Forestry Commission, landowners, local authorities & charitable organisations eg. Woodland Trust. Community involvement also promoted eg. The Big Tree Plant campaign to plant 1 million new trees, mostly in urban areas.

Carbon Capture & Storage

● Power stations and factories using fossil fuels can be made to capture and store emissions by laws and regulations. • However, suitable geologic sites may not be available and the technologies involved might be too expensive for developing countries. It also reduces profits, so economic priorities could be put first. ● In the UK, government investment in full-scale projects at a gas-powered plant in Scotland and coal-powered plant in Yorkshire were cancelled

Kyoto Protocol

Successes	Failures
Kyoto operates until 2020 Started a global approach to tackling anthropogenic climate change ↳ Was the beginning of regular UN conferences on climate change	Slow ratification. UK was one of the first but others struggled (Russia) or withdrew (USA, Japan, Canada), fearing economic impacts
The clean development mechanisms supports 75 developing countries in developing less polluting technology	Only industrialised countries were asked to sign, not developing nations. The top emitters • USA & China were left out of the agreement
Paved the way for new rules & measures on lew carbon legislation, such as the UK's 2008 climate change act. China is also slowing emissions	Complex trading systems were stated, allowing the trading of carbon credits, buying emission allowances from countries not needing them Carbon sinks were allowed to offset emissions ↳ Criticised for allowing polluters to polute
By 2012, emissions were 22.6% lower than the 1990 levels, well beyond the 5% goal	2015 showed a 65% ↑ above 1990 levels, mainly driven by India & China

COP21

↳ Had a number of new features compared to Kyoto:

• All countries were involved, not just developed ones
• Countries wreaked to bring proposed emissions reduction to the meeting, rather than negotiate them at the meeting
• Global warming's potential threats had a much larger public profile
• There was clarity over the overall aim (to limit warming below 2C)

The Paris Agreement

Considered as a limited success:

• Emissions pledges should reduce emissions from about 60 gigatonnes of Carbon per year by 2030, to around 55 gigatonnes
• However, emissions by 2030 need to be about 40-45 gigatonnes to limit warming to 2C and 30-35 gigatonnes to limit warming to 1.5C