How do we know that climate change is real?
Lots of people believe that climate change isn't real. Are governments and scientists lying to us? What is the evidence that climate change is real and a great danger to us all. Let's find out...
Climate change: what do we know about it?
Climate scientists have collected mountains of evidence that the planet’s climate is changing. There are many causes for climate change, but human activities are the primary cause.
"Scientific evidence for warming of the climate system is unequivocal."
- Intergovernmental Panel on Climate Change
The current warming trend is of particular significance because it unequivocally results from human activity since the mid-20th century and is occurring at a rate that has no precedent in recorded history.
Yes, the earth is warming up, but it's also undeniable that we're causing those changes. We're changing the atmosphere, ocean, and land, and it's causing changes in our biosphere.
Scientists have been able to see the big picture from Earth-orbiting satellites. With these advanced technological advancements they can collect many different types of information about our planet and its climate on a global scale.
This data was collected over many years and shows that there are strong signals for change in the climate.
In 1850, Charles Green demonstrated the heat-trapping nature of carbon dioxide and other gases.
NASA uses their ability to affect the transfer of infrared energy through the atmosphere in order to develop many instruments for use in space.
The best answer is that there is no question that increased levels of greenhouse gases cause Earth to warm in response.
Earth’s climate has always responded to changes in the amount of greenhouse gases in the atmosphere.
Old evidence can also be found in the layers of sedimentary rock.
It is important to understand the paleoclimate record and how it relates to global warming in order to understand the future climate changes.
Increasing carbon dioxide from human activity is about 250 times faster than it was from natural sources after the last Ice Age.
97 percent of climate scientists agree that the earth is warming due to human activity. Climate change has been observed over much of human history, so if it continues it could result in large losses in natural resources and food production.
There are many lines of evidence that suggest this is true.
What is the most compelling evidence for climate change?
Global Temperature Is Rising
The average surface temperature of the planet has risen about 2 degrees Fahrenheit (1 degrees Celsius) since the late 19th century. It's primarily due to increased carbon dioxide emissions and other human activities.
Most of the warming occurred in the past forty years. The last seven years have been the hottest.
The year 2020 was the warmest year on record.
Oceans Are Heating Up
The ocean has absorbed much of of the increased heat, with the top 100 meters (about 328 feet) of ocean displaying warming of more than 0.6 degrees Fahrenheit (0.33 degrees Celsius) since 1969. Our planet stores 90% of the increased heat in our oceans.
Ice Sheets Are Shrinking
The Greenland and Antarctic ice sheets have shrunk. Data from NASA shows that Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019 and Antarctica lost around 148 billion tons of ice per year.
Glaciers Are Disappearing
Glaciers are disappearing around the world. We are losing them in the Alps, Himalayas, Andes, Rockies, Alaska, and Africa.
Snow Cover Is Being Lost
Many studies have shown that spring snow cover is shrinking around the globe. Satellite observations show that this is happening much earlier than it did in the past.
Sea Levels Are Rising
Global sea level rose about 8 inches (20 centimeters) in the last century.
And since the early 1980s the rate has almost doubled, and the pace of growth appears to be increasing.
Arctic Sea Ice Is Vanishing Rapidly
Arctic sea ice has been melting rapidly in recent years. The decline in sea ice extent over the last several decades is quite dramatic.
Extreme Weather Events Are Becoming More Frequent
More high temperature records were set this year in the U.S. than ever before. Meanwhile, the number of record low temperature events decreased.
The U.S. has seen increased numbers of intense rainfall events in recent years.
Oceans Are Becoming More Acidic
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by 30%.
Increasing levels of greenhouse gases will have a dramatic effect on the climate and the weather.
The oceans have absorbed about 20% to 30% of all anthropogenic carbon dioxide emissions in recent decades. That's a lot of carbon dioxide!