In its latest report, the first working group of the IPCC does not only reconstruct past climate changes and observe those that are taking place today. Crucially, it also explores possible futures. The five new scenarios used in this report present possible evolutions of the climate throughout the 21st century as a function of greenhouse gas (GHG) emissions and of the evolution of human societies. The use of scenarios – which are plausible representations of an uncertain future – enable to explore different possible evolutions of human societies and their implications for the climate. The aim of these scenarios is not to predict the future – no probability is associated with the different scenarios – but to take into account the uncertainty linked to future human activities and to inform the decisions of States and more widely of societies. It is important to note that climate change is a broad topic so i will focus just on a little history on how the planet has gotten to the climate disaster we are experiencing today and how increased emissions results to increase in temperatures/
The term global warming is something that is now familiar to majority of people and in case you’re not, here is a simple quick definition. Global warming is the release of greenhouse gases resulting to increased surface and air temperatures.
For the past 2000 years global surface temperatures have stayed relatively constant until an unprecedented rate of warming in the mid-20th century.
How did we get here and what is causing global warming?
What is causing global warming?
The global temperature graph makes it clear that for several years now, average surface temperatures have consistently surpassed 1.5°C above their pre-industrial values. Let’s dig into these time periods a bit more closely to uncover more context around this phenomenon.
Industrial revolutions and advances, 1851–1935
An obvious, early anomaly on the visual worth exploring occurs between 1877–1878. During this time, the world experienced numerous unprecedented climate events, from a strong El Niño to widespread droughts. The resulting Great Famine caused the deaths of between 19–50 million people, even surpassing some of the deadliest pandemics in history.
Several economies later progressed into the Second Industrial Revolution (~1870–1914), followed by World War I (1914-1918). Overall, there was a focus on steel production and mass-produced consumer goods over these 80+ years.
Although these technological advances brought immense improvements, they came at the cost of burning fossil fuels—releasing significant amounts of carbon dioxide and other greenhouse gases. It would take several more decades before scientists realized the full extent of their accumulation in the atmosphere, and their resulting relation to global warming.
The modern world in the red zone, 1936–2020
The second half of the global temperature graph is marked by World War II (1939-1945) and its aftermath. As the dust settled, nations began to build themselves back up, and things really kicked into hyperdrive with the Third Industrial Revolution.
As globalization and trade progressed following the 1950s, people and goods began moving around more than ever before. In addition, population growth peaked at 2.1% per year between 1965 and 1970. Industrialization patterns began to intensify further to meet the demands of a rising global population and our modern world. In this time as well saw a boom in the plastic industry with growing markets and ever-increasing demand. Plastics manufacturers turned to making consumer products as an outlet for the materials they developed in the war. Polyester was introduced in the 1950s, and polypropylene, today one of the most used polymers in the world, got its start as a commodity in 1954, becoming a very useful polymer due to its adaptability. At this time no one predicted the devastating effects plastics would have on our environment. It was simply seen as a strong, flexible and durable material.
Fast forward to 2015 and the Paris Agreement comes into the forefront. Its goal is to limit global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, compared to pre-industrial levels. To achieve this long-term temperature goal, countries aim to reach global peaking of greenhouse gas emissions as soon as possible to achieve a climate neutral world by mid-century. Currently the earth has warmed to 1.1 degrees Celsius pre industrial levels. So the room for error is pretty small.
Today, we are still dealing with a growing fossil industry, unprecedented weather events, extinctions and collapsing ecosystems. To help better understand and mitigate climate change and its effects the IPCC was created. Its aim is to provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options.
Through its assessments, the IPCC determines the state of knowledge on climate change. It identifies where there is agreement in the scientific community on topics related to climate change, and where further research is needed. The reports are drafted and reviewed in several stages, thus guaranteeing objectivity and transparency.
The IPCC has put forward climate scenarios that show how certain amounts of GHG emissions will affect temperature.
Basically, these scenarios are categorized into 5 groups as shown in the graph below.
· Very low emissions SSP1-1.9
· Low emissions SSP1-2.6
· Moderate emissions SSP2-4.5
· High emissions SSP3-7.O
· Very high emissions SSP5-8.5
One important thing to note is that Global surface temperature will continue to increase until at least mid-century under all emissions scenarios considered. Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in CO2 and other greenhouse gas emissions occur in the coming decades.
According to the UN Environment Programme, emissions must fall by 25% before 2030 to keep increases within 2 degrees by 2100. 55 % reductions before 2030 are needed to limit the increase to 1.5 degrees.
What the scenarios translate to
Very low emissions
Warming is kept at 1.5 degrees. However, it overshoots to 1.5 degrees mid century after which it drops to 1.4 degrees.
This requires sharp CO2 cuts per decade, net zero by 2050 from every country and carbon capture.
CO2 cuts of 1 to 2 GT .Currently, the world emits about 43 billion tons of CO2 a year (2019). This includes total carbon emissions from all human activities, including agriculture and land use
Low emission scenario
Warming is kept just below 1.8 degrees Celsius
Intermediate scenario warming at 2.7
High emissions warming at 3.9
Very high emissions warming at 4.7
For the last three scenarios which all indicate temperatures above 2 degrees Celsius, take a look at the video explaining what happens once temperatures surpass the 2 degree barrier.
The findings of this report leave no excuse for delaying action on adaptation and mitigation. Indeed, in all the scenarios considered, warming exceeds the 1.5°C limit in the next twenty years. Immediate efforts are therefore required for adaptation, and this report helps us to identify unavoidable climate changes so that we can better prepare for them. In this report, the IPCC also reminds us that the objective of limiting warming to 1.5°C in the long term is not lost, via the SSP1-1.9 scenario in which warming is limited to 1.4°C at the end of the century after temporarily exceeding 1.5°C. However, this requires drastic and immediate decisions for mitigation.
To view the full report visit the IPCC website.
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