Why does climate change matter?
In 1965, scientists warned President Lyndon Johnson about the threat of disastrous climate change. In 1988, a NASA scientist testified before Congress about the dangers of global warming. For years, world leaders have called climate change a “defining issue of our era”.
The challenge of climate change is not a new one. Yet it still confronts us. Nineteen of the twenty hottest yearson record have happened since the year 2000. In fact, 2020 tied with 2016 as the hottest year since records began in 1880.
So, what is climate change? And why should we care about it?
What is climate change?
Climate change is any long-term change in the average weather patterns of a place over many years. It includes a number of different changes, such as heavier rainfall, increasing droughts, melting ice, and rising sea levels. It also includes global warming.
Global warming refers to the steady increase of the Earth’s temperature. Scientists have found that the average temperature of our planet has risen by around 2°F (1°C) since 1880. The excess heat caused by global warming in turn triggers large shifts in weather patterns. In other words, global warming is both a type of climate change and a cause of more climate change. So, what causes global warming?
Life on Earth depends on energy from the Sun. When the Sun’s energy reaches the surface of the Earth, it is absorbed by the Earth and then radiated upward as heat. While some of the heat then escapes into space, most of it is absorbed by gases in the Earth’s atmosphere and radiated back toward the Earth — heating the planet. This heating is called the greenhouse effect. The gases that stop heat from escaping the Earth’s atmosphere are called greenhouse gases.
Greenhouse gases are important to keeping the Earth warm enough for life. Without enough of these gases, the planet will become too cold for life, like Mars. But if there is too much greenhouse gas, the planet becomes too hot, like Venus. There are many gases that contribute to the greenhouse effect, one of the most important of which is carbon dioxide.
Carbon dioxide is important because the amount of it in the atmosphere has grown rapidly in the last few centuries. In fact, its concentration in the atmosphere has increased by nearly 50% since the start of the Industrial Revolution. So, what has caused carbon dioxide and other greenhouse gases to build up in the atmosphere in in the last few hundred years?
On one hand, greenhouse gases are emitted by natural sources. Our planet has experienced global warming and cooling before, along with other enormous climate changes. Ice ages and warm periods have happened in 100,000-year cycles for a least the last million years.
However, scientists have provided a lot of evidence that today’s global warming is happening a much faster rate than ever before. We also know that human activity over the last few centuries, from driving cars to large-scale farming, has caused a big increase in greenhouse gases.
The rapid increase in the Earth’s temperature coincides exactly with the rapid increase in human-generated greenhouse gas emissions. Virtually all climate scientists agree that global warming is almost certainly due to human activity.
So, how is climate change and global warming impacting our world? And what can we expect in the future?
How is climate change impacting our world?
The world is already 2°F (1°C) hotter than it was 200 years ago. If current trends continue, we can expect temperatures to increase by another 1°F as soon as 2030 to 2052 and by several more degrees by the end of the century. Even if greenhouse gas emissions were suddenly cut to zero, the amount of greenhouse gas already in the atmosphere would mean that hotter temperatures would persist for hundreds of years more.
One effect of a warmer world is more extreme weather events, like heatwaves, storms and droughts. More extreme weather has disastrous effects on human life and wellbeing, making the planet a much more difficult place in which to live.
Scorched land and floods already regularly destroy crops and farms across the world, reducing food supplies and increasing food prices. As global warming and climate change continue, the largest declines in food production are expected to happen in places that are already suffering from high rates of hunger. More extreme weather will only make food insecurity worse. But the threat to farms will be felt across the world, including in the United States. Even just last year, millions of bushels of grain were damaged and destroyed across Iowa by rare storms.
Beyond food production, extreme weather has many other serious effects on human health. In 2003, a heatwave in Europe killed at least 35,000 people and potentially even up to 70,000 people. At the same time, floods and warmer temperatures have also led to more disease around our planet. In fact, according to the WHO, climate change is expected to cause approximately 250,000 additional deaths per year from malnutrition, malaria, diarrhea and heat stress between 2030 and 2050.
Increasing heat has changed ecosystems all over the world, pressuring the animals and plants that live in them. Deserts are becoming dryer and larger. Forests are degrading, with less rainfall and more fire. At the world’s poles, ice sheets have shrunk. In just 2018–19, Greenland lost 530 billion tons of ice — that is the same weight as nearly 1.5 million Empire State Buildings. At the South Pole, Antarctica has lost nearly 4 trillion tons of ice since the mid-1990s. According to the United Nations, 1 million species are at risk of extinction across the world.
As land temperatures have soared, so too have ocean temperatures. Hotter oceans pose an existential threat to marine life. In just the last 30 years, half of the world’s coral reefs have died, taking with them some of the most diverse environments on our planet. In the next 20 years, up to 90% of coral reefs are expected to die.
Warming ocean temperatures and melting ice sheets have also caused ocean levels to rise 8 inches in the last century. Already, Pacific Island countries are under threat and some may become uninhabitable in the future. Closer to home, Miami is becoming one of the most vulnerable major coastal cities in the world.
The oceans are rising at an increasingly fast rate and could rise by another 3 feet or more by 2100, devastating coastal regions across the world. The New York City government has already earmarked $10 billion to protect the city from rising water. Even with just a few feet of ocean level rise, large parts of the city would be under water.
The impact of climate change has been felt unequally, within communities and across countries. Those with the least resources are also those who tend to be most exposed and susceptible to damages caused by climate change. In fact, climate change in itself drives inequality. A Stanford University study showed that the gap in economic output between the most productive and least productive countries in the world is 25% larger than it would have been without climate change. Climate change has created and will continue to create an increasingly unfair world.
So, why is climate change important?
Climate change is important because it is transforming our world in a way that makes it a fundamentally more difficult place to live. The Earth has survived enormous transformation in the past. But the cost of this transformation is real and high all those who inhabit our planet — for animals, plants, human wellbeing and livelihoods. Climate change is important because it risks future generations’ ability to live in a healthy world.
The scale of the challenge is enormous in its global reach, long-lasting impact and disastrous consequences. This means that the scale of the solution will also be enormous. Even to stay within 3°F (1.5°C) of warming, we will need to reach net zero carbon emissions by 2050. To stay within 4°F (2°C), we will need to reach net zero carbon emissions by 2070. These targets will be difficult to achieve.
But this is the second reason why climate change is important. Tackling the challenge of climate change can also bring enormous opportunities. Transitioning to a new, green economy creates jobs and economic benefits. It creates opportunities to come together as a global community and create a healthier, fairer world. Fundamentally, fighting climate change is a challenge that should inspire us and an endeavor that can unite us.
