Global Warming: What a 1.5°C World Would Look Like

By Abigail Meyers


The rate at which our planet is warming and the consequences we face by ignoring it is becoming increasingly clear. But what exactly will the impact of our actions look like? While predictions vary, scientists have developed general ideas of what the Earth could look like once we reach certain defining points. 1.5°C and 2°C are the basis for discussion surrounding solutions for global warming. Although only 0.5°C apart, the difference between the two is considerable. Carl Friedrich Schleussner, Head of Climate Science at Climate Analytics and Group Leader at Humboldt University Berlin, said 1.5°C and 2°C marks “the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions.”

The Paris Climate Agreement, an international treaty focused on climate change involving 196 parties at the time of its formation, set a goal to limit global warming to 1.5°C. Unfortunately, most potential solutions would include a temperature overshoot. This means that the global temperature would exceed the limit for a short period of time before being reduced to its original goal. Global temperature averages in 2020 were 1.15°C above those of preindustrial eras- meaning that it would be more than twice as difficult to stop global warming at 1.5°C than 2°C. Thus, sizable and immediate change is crucial. At the current rate of atmospheric warming, the atmosphere is predicted to reach 1.5°C between 2030 and 2052. By 2100, the sea level at 1.5°C would increase by 0.4 meters, and at 2°C, 0.46 meters; from this point, the sea level would only continue to increase. Excessive rising of sea levels is dangerous for a number of reasons. Flooding of land with lower elevations would cause significant damage;- potentially destroying crops, housing, and cities. Currently, we are on track to approach 5°C by the end of the century.

So why is 1.5°C such a significant turning point, and how different would this be from 2°C? To begin, global warming creates food insecurity, an increased risk of drought and flooding, and a variety of health issues. Johan Rockström, Professor and Director of the Stockholm Resilience Center, reports that 2°C “contains significant risks for societies everywhere; 1.5°C looks much more scientifically justifiable.” At 2°C, parts of southwest Asia could become uninhabitable without permanent air conditioning. Corn crop yields in Africa could be cut in half. Halting global warming will be extremely difficult, but isn’t impossible. Stopping warming at 1.5°C could prevent an ice-free arctic in summers, prevent further damage to the Amazon Rainforest, and cease melting of the Siberian tundra. The World Resources Institute presents the differences between a 1.5°C and a 2°C world, citing major concerns, such as sea-level changes and species extinction.

Limiting warming to 2°C would require humans to reduce annual emissions by 20% below the levels of 2010 by 2030. In order to cease warming at 1.5°C, emissions need to drop by approximately 45%. Reduction of carbon footprints in large corporations is crucial, but individual contributions can be just as important. The most effective individual changes we can make are lowering our carbon usage by using alternatives such as solar power or electric cars and consuming a more plant-based diet. Small changes make a substantial impact over time. Ultimately, it is essential to reach zero carbon emission levels. Realistically, the goal of 2°C would need to be achieved by 2050, while 1.5°C would need to be achieved by 2075. 

While all greenhouse gasses are detrimental, carbon dioxide (CO2) is particularly harmful because of how long it remains in the atmosphere. “The world has just gambled its future on the appearance, in a puff of smoke, of a carbon-sucking fairy godmother,” stated Kevin Anderson, a climate scientist at the University of Manchester. Chemical removal of carbon dioxide is extremely expensive. For this reason, many have resorted to biological processes, such as planting trees. This solution is gradual, yet still effective.

A number of solutions have been proposed, but overall, we have failed to take action. Groups such as the Paris Climate Accord and the Intergovernmental Panel on Climate Change have made significant progress, but more effort is necessary to reverse the damage. Societal issues pose significant barriers to progress, as large swaths of the population are not committed to fighting global warming. Taking immediate action to reverse the damage already done is imperative. Although challenging, a 1.5°C warmed world remains an achievable goal.