How do we know that the climate is changing?

Arabia Weather - NASA published a report on climate change, and experts said that the Earth’s climate has changed throughout history. In just the last 800,000 years, there have been eight cycles of ice ages and warmer periods, and the end of the last ice age about 11,700 years ago marked the beginning of the era of modern climate and human civilization.

The role of satellites in knowing the changes that occur in the climate

According to NASA, satellites orbiting the Earth and modern technologies have helped scientists see the full picture and collect many different types of information about our planet and its climate around the world. This data, collected over many years, reveals signs and patterns of climate change.

Scientists demonstrated the greenhouse effect of carbon dioxide and other gases in the mid-19th century. Many of the scientific instruments NASA uses to study our climate focus on how these gases affect the movement of infrared radiation through the atmosphere. From the measured effects of increasing these gases, there is no doubt that increased levels of greenhouse gases are causing the Earth's temperature to rise in response.

The evidence for rapid climate change is compelling:

Global temperature rise

The planet's average surface temperature has risen by about 2 degrees Fahrenheit (1 degree Celsius) since the late 19th century, a change driven largely by increased emissions of carbon dioxide into the atmosphere and other human activities. Most of the global warming has occurred in the past 40 years, with the last seven years being the warmest. 2016 and 2020 are tied as the warmest years on record.

The ocean is getting warmer

Much of this increased heat has been absorbed by the ocean, with the top 100 meters (about 328 feet) of the ocean showing a temperature rise of 0.67°F (0.33°C) since 1969. 6 The Earth stores 90% of its excess energy in the ocean.

Ice sheets are shrinking

The mass of the ice sheets in Greenland and Antarctica decreased. Data from NASA's Gravity and Climate Recovery Experiment show that Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019, while Antarctica lost about 148 billion tons of ice per year.

Glaciers are retreating

Glaciers are retreating almost everywhere around the world – including the Alps, Himalayas, Andes, Rocky Mountains, Alaska, and Africa.

Snow cover is decreasing

Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that snow is melting earlier.

Sea level rise

Global sea levels have risen by about 8 inches (20 centimeters) in the past century. However, the rate in the past two decades is almost double the rate of the last century and is accelerating slightly each year.

Extreme events are increasing in frequency

The number of record high temperatures in the United States has been increasing, while the number of record low temperatures has been decreasing, since 1950. The United States has also experienced an increasing number of extreme rainfall events.

Ocean acidification is increasing

Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. 13, 14 This increase is due to humans emitting more carbon dioxide into the atmosphere, thus absorbing more of it into the ocean. The ocean has absorbed between 20% and 30% of total human-made carbon dioxide emissions in recent decades (7.2 to 10.8 billion metric tons per year).