Why 1.5°C matters: The impacts of global warming on our planet and our future

Climate change is one of the most pressing challenges of our time. The scientific consensus is clear: human activities are causing the Earth to warm at an unprecedented rate, and this warming has serious consequences for people and nature.

But how much warming is too much? And what are the differences between limiting the temperature rise to 1.5°C or 2°C above pre-industrial levels by the end of this century?

In this blog post, we will explore these questions and highlight some of the key impacts of climate change at different levels of warming, based on the latest research and data.

What is the 1.5°C climate pledge?

The 1.5°C climate pledge is a global commitment to limit the average temperature rise of the Earth to 1.5 degrees Celsius above pre-industrial levels by the end of this century. This goal was agreed upon by nearly 200 countries in the Paris Agreement of 2015, as a way to avoid the worst impacts of climate change on people and nature .

However, achieving this target will require unprecedented and urgent action to reduce greenhouse gas emissions and remove carbon dioxide from the atmosphere. If we fail to do so, we will face increased risks to health, livelihoods, food security, water supply, human security, and economic growth. We will also witness more extreme heatwaves, rising sea levels, and the loss of most coral reefs .

The 1.5°C pledge is not just a number, but a lifeline for our planet and our future.

What are the top five impacts of 1.5°C warming?

According to various sources, here are five top impacts of 1.5°C warming, compared to higher levels of warming:

• Extreme heat: With a 1.5°C increase, extreme hot days in the mid-latitudes will be 3°C hotter (5.4°F) than pre-industrial levels. This will increase the risk of heat-related mortality, morbidity, and lower labour productivity. With a 2°C increase, these risks would be even higher, affecting more regions and more people.
• Rising sea levels: With a 1.5°C increase, sea levels are projected to rise by 2100 by 0.26 to 0.77 meters (0.85-2.52 feet) relative to 1986-2005. This will expose millions of people to coastal flooding and erosion, especially in low-lying areas and small island states . With a 2°C increase, sea level rise would be faster and higher, affecting up to twice as many people.
• Declining biodiversity: With a 1.5°C increase, up to 18% of insects, 16% of plants, and 8% of vertebrates are projected to lose over half of their climatically determined geographic range. This will threaten their survival and the ecosystem services they provide . With a 2°C increase, these losses would be larger, affecting up to twice as many species.
• Melting Arctic sea ice: With a 1.5°C increase, the Arctic Ocean is projected to become ice-free in September once per century. With a 2°C increase, this would occur once per decade. This will have profound consequences for the wildlife, indigenous peoples, and climate feedbacks of the region . For example, less sea ice means less reflection of sunlight back into space, which leads to more warming.
• At-risk coral reefs: With a 1.5°C increase, the end of the century projection is that 70% of tropical coral reefs are at risk of severe degradation due to temperature-induced bleaching. With a 2°C increase, virtually all (more than 99%) would be lost. This will affect the biodiversity, fisheries, tourism, and coastal protection that reefs support . For example, coral reefs provide habitat for about a quarter of all marine species and support the livelihoods of about half a billion people.

What can we do to limit warming to 1.5°C?

Limiting warming to 1.5°C is not impossible, but it will require rapid and deep cuts in greenhouse gas emissions from all sectors of society. According to the IPCC report on 1.5°C, global net human-caused emissions of carbon dioxide need to fall by about 45% from 2010 levels by 2030 and reach net zero around mid-century.

This means that we need to transform our energy systems from fossil fuels to renewable sources such as solar, wind, and hydro. We also need to improve our energy efficiency, reduce our consumption and waste, and adopt more sustainable lifestyles. We need to protect and restore our natural carbon sinks such as forests, wetlands, and soils. And we need to develop and deploy technologies that can remove carbon dioxide from the atmosphere and store it safely.

We also need to adapt to the impacts of climate change that are already happening or unavoidable. This means that we need to build resilience in our communities, infrastructure, and ecosystems. We need to enhance our disaster risk management, early warning systems, and social protection. And we need to support the most vulnerable and marginalized groups, such as women, children, indigenous peoples, and the poor.

All these actions require strong political will, international cooperation, public awareness, and individual responsibility. They also require a vision of a more sustainable and equitable future for all.

Conclusion

Climate change is a global challenge that affects everyone and everything on Earth. The difference between 1.5°C and 2°C of warming may seem small, but it can have huge implications for the world we live in and the world we leave behind for future generations.

The 1.5°C climate pledge is a bold and ambitious goal that reflects the urgency and the opportunity of the situation. It is not a lost cause, but a lifeline. It is not a burden, but a benefit. It is not a sacrifice, but a chance.

We have the knowledge, the technology, and the resources to limit warming to 1.5°C. What we need is the courage, the commitment, and the action to make it happen.

References:

: 1.5 or 2 degrees Celsius of additional global warming: Does it make a difference?

: The impacts of climate change at 1.5C, 2C and beyond - Carbon Brief

: Special Report on Global Warming of 1.5 °C - IPCC

: Special Report on Global Warming of 1.5 °C - Wikipedia

: Half a Degree and a World Apart: The Difference in Climate Impacts Between 1.5˚C and 2˚C of Warming