What Does 1.5c Mean In Global Warming?

What is the 1.5c degree change?

Whenever the weather gets a little warmer, most of us would not feel the difference that 1.5°C makes. However, if the global average temperature changes by 1.5°C, it will paint a completely different picture.

Global temperature is the average temperature over the entire surface of Earth. It is used as an indicator of climate change and symbolises how we as human beings are affecting the vital systems on Earth. Each little change in the global temperature can wreak havoc like rising sea levels, changes in biomes, and more extreme weather patterns. Hence, it is very different from the local temperature reading and deserves much more attention.

Crop Field Drying Out.

What happens at 1.5c?

It is no secret to anyone that the Earth has gone through an ice age. Then came warmer periods when the dinosaurs roamed the Earth. Naturally, there have been times when the global temperatures were higher and lower than it is now. Historically, there were periods when the global temperatures had been so warm that all glaciers permanently melted, and no new ones would form for millions of years. Then there were periods when the global temperatures were so low that large parts of the world were covered in sheets of ice that were several kilometres thick. Studies suggest that between these periods, the global temperatures were as low as 10°C and as high as 23°C. Therefore, we measure the change in global temperatures and humanity's impact on the climate, and it is not looking good.

Industrial revolution - pros and cons

For the last 10,000 years or so, the planet has had an unusually stable climate. The global temperatures have only gone through minor changes, which has allowed humankind to live in a stable environment and make extraordinary advancements. However, if this stability changes, humanity will face extreme hardships. We realise today that the difference between global temperatures rising by half a degree could translate to millions of people and countless species affected by droughts, sea-level rise, heatwaves, water scarcity, and food shortages. At this point, we are no longer trying to stop and reverse the change in global temperatures. We are simply trying to make sure the global temperatures do not rise too much. Unfortunately, the industrial revolution came with a massive discharge of various gases into our atmosphere that severely impacted the climate. Right now, the global temperature is closing in at 15°C, which will be more than a 1°C increase pre-industrial level, and if we let this continue, there will be irreversible damages to our environmental system.

Polar bears searching for food

If the temperatures rise by only 1.5°C:

  • 70-90% of all coral reefs will disappear, leaving irreversible damage to the oceans. The coral reefs are essential for large portions of the world's marine populations.

  • An average of 0.4m increase in sea levels will put entire islands underwater and affect coastal cities, towns, and villages around the globe. They will have to deal with floodings and partial submergence, threatening the survivability of these habitats.

  • Roughly 8% of all plant life, 4% of all vertebrates and 6% of all insects will lose more than half of the space they are currently living in.

Will Venice survive the 1.5c change

  • 14% of the world will experience severe heat waves at least every five years. The wildfires we have seen rampaging the world for the last couple of years will be more frequent and widespread.

  • 7% of all ecosystems will shift to a new biome which can already be seen in the Sahel and Arctic tundra, where new plant species is pushing away other plants, leaving severe marks on the land. In the Sahel, woodlands are disappearing, leaving the land more vulnerable and the people without any firewood to cook food or heat up in the cold. In the Arctic, new vegetation is making its way and pushing away habitats for the wildlife.

If the global temperatures continue to rise by half a degree Celsius or more, the impact on our environmental system will double and even triple in some cases.

What should we do?

Globally, we need to cut emissions to the point that we reach a net-zero emission level by 2050. It means that we cannot let out more greenhouse gases into the atmosphere than the Earth can absorb. If we fail to control the greenhouse gas emissions, global temperatures will continue to rise, and we will end up in a calamitous scenario. Now to the clichés: For change to happen, we need to be the change. As individuals, we can change our diets to reduce meat and dairy consumption, reduce consumption and waste, drive and fly less, use more public transportation, use more efficient appliances, and install better insulation systems to depend less on air conditioning in hot regions and heating in cold areas.

Unfortunately, it is no longer enough just to cut emissions.

The most critical mitigation strategy right now is to absorb carbon dioxide from the atmosphere and find new ways to store it without letting it back into the atmosphere.

That includes making sure the right people are in power and supporting the right companies and organisations, driving initiatives and strategies such as absorbing carbon dioxide, green energies that are easily accessible. Our task as citizens, consumers, and community members is to demand that all major players do their part. We can vote for the right politicians, buy from sustainable businesses, and be active in our communities.

Most of all, we need to demand accountability and transparency. If companies and governments do not want to show or explain what they do, that is a change we should all advocate for.

About Fredrik Andersson

Engineer, writer, translator, and hobby musician.

"Brought up in the countryside outside Stockholm, Sweden, I grew up reading any book I could find, playing any instrument that had the misfortune of falling into my hands, and engineering whatever I could imagine. 28 years in, I’m still the same, just with a fancy education and better imagination."