The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.
Scientific evidence for warming of the climate system is unequivocal.- Intergovernmental Panel on Climate Change
The current warming trend is of particular significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.1
Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate.
The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.2 Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response.
Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that current warming is occurring roughly ten times faster than the average rate of ice-age-recovery warming.3
The evidence for rapid climate change is compelling:
Global temperature rise
The planet's average surface temperature has risen about 2.0 degrees Fahrenheit (1.1 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.5 Most of the warming occurred in the past 35 years, with 16 of the 17 warmest years on record occurring since 2001. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months. 6
The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969.7
Shrinking ice sheets
- The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005.
Image: Flowing meltwater from the Greenland ice sheet
Vital Signs: Land Ice
An indicator of the current volume and the Antarctica and Greenland ice sheets using data from NASA’s Grace satellite.
Global Ice Viewer
An interactive exploration of how global warming is affecting sea ice, glaciers and continental ice sheets world wide.
- Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.9
Image: The disappearing snowcap of Mount Kilimanjaro, from space.
Decreased snow cover
Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.15
Sea level rise
- Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century.4
Image: Republic of Maldives: Vulnerable to sea level rise
Declining Arctic sea ice
- Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.8
Image: Visualization of the 2012 Arctic sea ice minimum, the lowest on record
Earth’s vital signs: Sea ice
An indicator of changes in the Arctic sea ice minimum over time. Arctic sea ice extent both affects and is affected by global climate change.
Interactive: Global ice viewer
An interactive exploration of how global warming is affecting sea ice, glaciers and continental ice sheets worldwide.
NASA’s Operation Icebridge mission
NASA’s Operation IceBridge images Earth's polar ice in unprecedented detail to better understand processes that connect the polar regions with the global climate system.
The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.10
Precipitation Measurement Missions
The official website for NASA's fleet of Earth science missions that study rainfall and other types precipitation around the globe.
Earth’s water is stored in ice and snow, lakes and rivers, the atmosphere and the oceans. How much do you know about how water is cycled around our planet and the crucial role it plays in our climate?
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent.11,12 This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.13,14
A List Of The Most Impressive Research Paper Topics On Global Warming
Ecology is a very important science as it deals with many environmental problems and tries to solve them. We can hear about global warming threat almost everywhere. Some people think that it is not serious, but its results can be observed even now, when the average year temperature continues to grow.
The research of global warming includes various branches of science, because all of them are interconnected. Here is a list of the essay topics on global warming that shows the problem in various aspects. Mind that these are only the examples. All these topics can be studied from various points and different methods can be applied.
- What is deforestation and how is it connected to the growth of the average temperature?
- What is the impact of the industrial gases on the planet’s atmosphere?
- Why does the greenhouse effect occur and what are its consequences on the human life?
- Is carbon dioxide the main reason of global warming?
- Is global warming a real danger or just a mistake caused by measurement anomaly?
- Temperature fluctuations in history – a brief analysis.
- Is the growth of the automobile industry responsible for global warming?
- Is global warming a temporary phenomenon?
- What are peculiarities of the temperature growth in the medieval period?
- How dangerous can be the threat of floods caused by global warming effect?
- Are droughts and storms caused by global warming effect?
- How can global warming change human behavior?
- What territories will suffer more from global warming?
- What is the influence of the temperature growth on the animal world in North America?
- Can rapid changes in the temperature cause quick evolution of the plants?
- Is global warming a way to manipulate people’s minds?
- How can we adapt crop farming to global warming conditions?
- Is global warming a result of the endless energy race?
- What are the best ways to fight global warming?
- How can children learn about dangers of the greenhouse effect?
- What are the most famous research organizations studying global warming?
- Is global warming an ecological problem or should it become an all-national question?
- What alternative energy sources can decrease the rate of the temperature growth?
- How do solar spots influence Earth’s atmosphere?
- Can global warming make some animal species disappear?
- Are ozone holes a result of the human activity or natural phenomenon?
- Is the threat of ice melting real?
- What unusual weather conditions are caused by climatic changes?