Is Global Warming a Modern Phenomenon?

Global warming is a hot-button topic in today's news, but perhaps if the world had acted on it when it was first feared, we wouldn't be dealing with it now. In 1896, a Swedish scientist named Svante Arrhenius became the first person to link the Earth's temperature with carbon dioxide concentrations in the atmosphere, and he warned that the burning of fossil fuels could lead to more carbon dioxide and therefore warmer temperatures. No one paid much attention, even as Arrhenius and colleague Thomas Chamberlin worked out calculations to show how human activity would lead to climate change. They figured out that the natural greenhouse effect on Earth keeps the planet at approximately 59 degrees F (15 degrees C), but that doubling the carbon dioxide concentration would raise it to 68 degrees F (20 degrees C). Despite the work, people generally maintained that human activity did very little to affect the Earth, and that things like solar activity and ocean circulation had much more to do with how cold or hot the planet would get. Today, of course, approximately 97 percent of all climate scientists agree that people are causing climate change.

A hot topic:

• The five warmest years on record have occurred since 2010.
• On average, Greenland has lost 286 billion tons of ice a year since 1993, while Antarctica has lost 127 billion tons per year.
• During the 20th century, global sea levels rose about 8 inches (20.3 cm); the rate in the last two decades is almost twice as much.

Frequently Asked Questions

Is global warming a recent occurrence in Earth's history?

No, global warming is not exclusively a recent occurrence. The Earth has experienced natural climate fluctuations over millions of years due to factors like volcanic eruptions, variations in solar radiation, and changes in the Earth's orbit. However, the rapid warming observed since the Industrial Revolution is unprecedented and largely attributed to human activities, particularly the burning of fossil fuels.

What evidence supports the idea that current global warming is human-induced?

Multiple lines of evidence support human-induced global warming. According to the Intergovernmental Panel on Climate Change (IPCC), the concentration of greenhouse gases such as carbon dioxide has significantly increased due to human activities since the 1750s. This rise correlates with a marked increase in global temperatures, sea-level rise, and the melting of ice caps and glaciers.

How much has the Earth's temperature risen in recent times?

Since the late 19th century, the Earth's average surface temperature has risen by about 1.18 degrees Celsius (2.12 degrees Fahrenheit), with most of the warming occurring in the past 40 years, as reported by NASA. The last decade was the warmest on record, highlighting the accelerating pace of temperature increase.

What role do greenhouse gases play in global warming?

Greenhouse gases, such as carbon dioxide, methane, and nitrous oxide, trap heat in the Earth's atmosphere, creating a 'greenhouse effect.' This natural process is essential for life, but human activities have increased the concentration of these gases, enhancing the effect and leading to more heat being retained, thus warming the planet at an unnatural rate.

Can natural processes alone account for the current rate of global warming?

Natural processes cannot fully account for the current rate of global warming. While natural factors like solar irradiance and volcanic activity do influence climate, their contributions to recent warming are minimal compared to the impact of anthropogenic greenhouse gas emissions. Studies show that the current warming trend is primarily the result of human activity.

What are the potential long-term impacts of global warming?

The long-term impacts of global warming are far-reaching and potentially severe. They include rising sea levels, more frequent and intense extreme weather events, loss of biodiversity, and disruptions to agricultural productivity. According to the IPCC, these changes can lead to resource scarcity, health risks, and economic challenges, affecting millions of people worldwide.