IPCC AR6 Climate Summary

https://www.ipcc.ch/assessment-report/ar6/ 

The IPCC is an intergovernmental panel that deals with climate change. The Sixth Assessment Report, finalized and released on March 20, 2023, summarizes the state of knowledge of climate change, its impacts, and possible solutions. These findings are split into three main groups, SPM.A Current Status and Trends, SPM.B Future Climate Change, Risks, and Long-Term Responses, and SPM.C Responses in the Near Term. 

CURRENT STATUS AND TRENDS

Human activities usually regarding the emissions of greenhouse gasses have raised the general temperature of subatmospheric Earth with temperatures reaching 1.1°C (33.98) above 1850-1900 in 2011-2020. Global average surface temperature was 1.09 [0.95 to 1.20]°C higher in 2011–2020 than 1850–1906, with larger increases over land (1.59 [1.34 to 1.83]°C) than over the ocean (0.88 [0.68 to 1.01]°C). Over this period, it is likely that well-mixed greenhouse gasses (GHGs) contributed a warming of 1.0°C to 2.0°C. Although GHGs emitted by human activities generally heat the earth, aerosols are released into the atmosphere resulting in a cooling effect of 0.0°C to 0.8°C. Natural events also changed global surface temperature by –0.1°C to +0.1°C, and internal variability changed it by –0.2°C to +0.2°C. Global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2000 years mainly as a result of human GHG emissions. These emissions as it is are heating up the earth but the rate of outflow is increasing as well. Every year that passes means more GHG emissions than the year before. In 2019 a huge barrier was broken, concentrations of Methane and Nitrous Oxide CO2 were at the highest in the last 800,000 years, and CO2 concentrations in the atmosphere were higher than ever before in the last 2 million years. If we do not break the cycle of polluting the air, the ecological tipping point and collapse of the environment is soon to be upon us. Despite the general warming of the earth, contrasts of emissions from different regions of the planet do exist. According to A.1.5, “In 2019, around 35% of the global population live in countries emitting more than 9 tCO2-eq per capita11 (excluding CO2-LULUCF) while 41% live in countries emitting less than 3 tCO2-eq per capita; of the latter a substantial share lacks access to modern energy services. Least Developed Countries (LDCs) and Small Island Developing States (SIDS) have much lower per capita emissions (1.7 tCO2-eq and 4.6 tCO2-eq, respectively) than the global average (6.9 tCO2-eq), excluding CO2-LULUCF. The 10% of households with the highest per capita emissions contribute 34–45% of global consumption-based household GHG emissions, while the bottom 50% contribute 13–15%”. This means that developed states even with little population account for the majority of greenhouse gas emissions. Sadly the emissions put out by the majority affect everybody on the planet. Not only is the arctic melting, but direct impacts on humans can be easily observed as 3.3 to 3.6 billion people live in places highly vulnerable to climate change. Beside the commonly used climate change side effect, sea level rise, there are other ways global warming negatively impacts the environment including, heatwaves, heavy precipitation, droughts, and tropical cyclones. This affects humans because it destroys agriculture, constructions, economies, and leads to the direct loss of life.  Between 2010 and 2020, human mortality from floods, droughts and storms was 15 times higher in highly vulnerable regions, compared to regions with very low

Vulnerability. As these natural disasters become more common, food and water scarcity becomes a problem, leading to millions of deaths. And where there is hunger, poverty and diseases are just around the corner. These events are not just going to appear in the future if we do not slow our GHG emissions down, they are currently happening in places like Africa, Asia, South and Central America, ETC. But it is not only rural areas being affected, cities even in temperate areas are too. In urban areas, observed climate change has caused adverse impacts on human health, livelihoods and key infrastructure. Hot extremes have intensified in cities. Urban infrastructure, including transportation, water, sanitation and energy systems have been compromised by extreme and slow-onset events14, with resulting economic losses, disruptions of services and negative impacts to well-being. Some adaptation has been done to counteract this however, the financial budget for both hard and soft methods are insufficient for major contribution. This can be easily seen through the recurrence of environmentally friendly resources and methods based on average personal and regional tax income, although many citizens are pushing for more spending in this sector. The result of this is multiple policies like The UNFCCC, Kyoto Protocol, and the Paris Agreement being internationally signed to limit the human effect on the environment. The policies opt for a more environmentally safe alternative to the usual polluting practice. Examples of these are, solar and wind turbines for electricity instead of oil and gas combustion, electric cars instead of gas ones, small farms on building roofs instead of forest land, etc. These policies have slowed down the effects of Global warming but yet it is not enough to counter or even lessen the total emissions.

FUTURE CLIMATE CHANGE, RISKS, AND LONG TERM RESPONSES

The chart following this text is a map of the world and weather patterns based on global temperatures from human causes

In the future even more species than today will become extinct. This event is in particular but not limited to the equatorial region. This region is also subject to the highest wet bulb temperatures. Wet bulb temperatures are temperatures with combined humidity and thermometer temperatures. This means that the equatorial region will have the highest number of heat related deaths. Because of this extreme heat, crop yield near the equator will be decreased while favorable temperatures reach higher up, to places with less fertile soil. This same phenomenon will occur with fish catch. Fish will migrate to cooler waters higher north and further south, thus fish yield will be less near the equator. According to B.3, “Some future changes are unavoidable and/or irreversible but can be limited by deep, rapid, and sustained global greenhouse gas emissions reduction. The likelihood of abrupt and/or irreversible changes increases with higher global warming levels. Similarly, the probability of low-likelihood outcomes associated with potentially very large adverse impacts increases with higher global warming levels.” This system can be slowed and in some cases reversed but only in the near term as adaptation options will only become less effective with increasing global warming. With increasing global warming, losses and damages will increase and additional human and natural systems will reach adaptation limits. This can be avoided by awarding benefits for helping the environment in some way. The goal of limiting human impact on the environment can be done with a net zero emission policy. This means that no GHGs are pumped into the atmosphere, if this is done, nothing needs to be done about the already existing CO2 in the air, it will be absorbed back into the earth by vegetation or by natural means. This also means that fossil fuels would be banned from society and if they had to emit carbon they would first have to take it out of the air, also requiring deforestation to come to a near halt. All global modeled pathways that limit warming to 1.5°C (>50%) with no or limited overshoot, and those that limit warming to 2°C (>67%), involve rapid and deep and, in most cases, immediate greenhouse gas emissions reductions in all sectors this decade. For example if you were to limit warming to 1.5 C you would need 16% or less of emissions in 2050 compared to 2019. If you were to limit it to 2 C, you would need 36% or less emissions in 2050 compared to 2019, both huge cuts into our global GHG emissions. This implies that limiting warming to 1.5°C and 2°C requires rapid, deep and in most cases immediate greenhouse gas emission reductions. 

RESPONSES IN THE NEAR TERM

As the amount of pollutants emitted into the atmosphere grows and the amount of GHG able to be absorbed back into the earth decreases, the window for opportunity to secure a liveable and sustainable future for all is quickly closing. To slow this effect down, we must implement near term responses. This can be done by funding projects, educating the people, creating policies, and improving the private sector. Near term action slows the progression of climate change and allows people time to develop and implement more effective large scale and long term solutions. Long term and large solutions need longer times compared to near term because they are of a larger scale and thus need more funding to start up. Near term solutions include, lower use and more sustainable energy supply, more efficient water, livestock, and land use, sustainable settlements and infrastructure, and a more environmentally aware economy, livelihood and society. According to C.6,  “Effective climate action is enabled by political commitment, well-aligned multilevel governance, institutional frameworks, laws, policies and strategies and enhanced access to finance and technology. Clear goals, coordination across multiple policy domains, and inclusive governance processes facilitate effective climate action. Regulatory and economic instruments can support deep emissions reductions and climate resilience if scaled up and applied widely. Climate resilient development benefits from drawing on diverse knowledge.” This means that government structure and policy is the framework that environmentally friendly systems rely on. The systems however cannot exist without the funding allowing them to be. By changing government policy, more effective and larger scale projects can be funded to combat global warming.

FUTURE DATA

AR5, the IPCC Synthesis Report released in 2014, proved to have lower rates of change and certainty in nearly all sectors in relation to climate change such as the financing of mitigation and adaptation (A.3.6), global warming scenarios (B.1.1), and climate-related risks (B.2.2). The essence of this was spoken in C.1.1, “Evidence of observed adverse impacts and related losses and damages, projected risks, levels and trends in vulnerability and adaptation limits, demonstrate that worldwide climate resilient development action is more urgent than previously assessed in AR5”. Updated climate predictions based on new data is needed in order to more accurately predict further climate change events and future rates of emissions.