“Climate change” and “global warming” are often used interchangeably, which has caused confusion, misunderstanding, and false conclusions about both terms. The terms have distinct meanings (explained below). Similarly, the terms "weather" and "climate" are sometimes confused. “Weather” refers to day-to-day or weekly short-term events, and “climate” refers to long-term persistent changes in typical weather patterns occurring over decades to millions of years.
Global Warming refers to the increased retention of heat in Earth's atmosphere--heat that would normally radiate into space, but does not, because of the increase in heat-retaining CO2, methane and water vapor in the atmosphere. This retained heat then increases the temperature of the world's oceans and land masses.
The oceans are the main driver of weather and climate. As the oceans warm, the oceanic weather engine destabilizes, leading over time to extreme climate changes worldwide—extreme cold and heat, increased strength of hurricanes; abnormal flooding, atmospheric rivers, snowstorms, droughts, and extensive wildfires; accelerated ice and glacial melt; dying coral reefs; and increasingly unlivable temperatures in some parts of the world.
Any of the foregoing weather events could occur as an “abnormal” event. When abnormal events occur regularly over many years, a new weather pattern has emerged, which is called “climate change”.
Hence global warming over the long-term causes climate change.
More detailed information from NASA and NOAA is available here.
The Mistaken Conclusion
Climate change deniers and climate scientists all seem to agree that Earth's temperature and CO2 levels have fluctuated, increasing and decreasing, over millions of years.
Because of this verifiably factual data, deniers conclude this is just Earth doing its normal thing, so no worries, and everything will be just fine...
This mistaken conclusion ignores several crucial pieces of data:
The CO2 levels have increased quickly and substantially since pre-industrial times. This increase began with large-scale use of fossil fuels around 100 years ago. It has been increasing ever since to its present daily CO2 levels.
The methane levels, a worse greenhouse gas than CO2, has also increased substantially and proportionately with cattle/beef production worldwide.
Because of warming temperatures, water vapor has been increasing proportionately. Water has the highest specific heat of all the greenhouse gases—meaning water vapor retains more atmospheric heat than either CO2 or methane.
And very importantly, these past changes occurred over thousands, tens of thousands, or millions of years. This gave lifeforms that existed during those past changes time to adapt. The changes now have occurred in less than 100 years and the changes are accelerating—that’s not enough time for many lifeforms, including humans, to adapt. For example, because the oceans are warming so quickly, coral reefs are dying, which has a domino effect on oceanic life and then, ultimately, on planetary life.
Global temperatures are rising as measured by satellites. These temperatures so measured correlate strongly with land-based temperatures taken over the past 150 years in various countries. And because temperatures are rising, there is increased ice melt and consequent sea level rise.
It doesn't matter that this has happened 15, 200, or 500 million years ago. Humans did not live on the planet 15 million years ago, but we do NOW. And we have numerous coastal cities worldwide, each populated by 10 to 30 million or more people. The climate change deniers are missing the most important consequences of all:
Our major cities will be flooded or under water, displacing close to a billion people worldwide. And at what cost???
Millions of years ago, when humans did not exist on the planet, temperatures were way higher and CO2 levels were way higher (underscoring the correlation of CO2 rise with temperature rise). The issue is, humans are not adapted to breathe substantially higher concentrations of CO2 (plants will do fine [18], but humans aren't plants), and we are not adapted to substantially higher temperatures.
Because these recent climate changes are occurring over a mere 100 years or less and are increasing at a quickening rate, many life forms, including humans, will not have time to adapt to the changes.
No. Everything won't be fine just because it happened millions of years ago! [13][14][15][16][18]
Climate change is increasingly disastrous. In the last 5 years, with every year setting a new record, we've seen:
Deadly heat, every year the hottest on record and 2024 is forecast to be the hottest yet [1].
U.S. wildfires burning over 32 million acres [2] which is projected to increase [3]. Wildfires in Europe burned an area equivalent to one-fifth of Belgium (1.6 million acres) [4]. The Texas wildfire, second largest in U.S. history has burned over a million acres [19].
Major weather disasters, causing nearly 2,000 deaths and over $600 billion in damage. [5]
The western half of the U.S. experienced the worst drought in over 1,200 years [6]. A record-breaking drought has caused some rivers in China to dry up– including parts of the Yangtze, the third largest river in world providing drinking water to 400 million people – affecting hydropower, halting shipping, and forcing major companies to suspend operations [7]
Deadly heat waves have caused strange infrastructural events around the world: For example, historically hot temperatures in London and China have buckled bridges and airport runways. In Texas, water mains have burst. [8]
Due to sea-level rise, eastern coastal cities from Florida to Massachusetts regularly experience drainpipe flooding, which causes costly damage.[9][10]
And if all of this is not sobering enough, a glacier in Antarctica that scientists have dubbed “the doomsday glacier” has been in “rapid retreat” and is melting much faster than previous predictions. Without this glacier and its supporting ice shelves, sea levels could rise by three to ten feet globally, causing entire coastal communities to flood. Major cities around the United States and across the globe could be partially underwater in the coming decades. Think about the mass dislocation, turmoil and international tensions that these displacements will cause.[11]
California received its typical 9 months of rain in 36 hours due to an abnormal “atmospheric river” causing millions in damages and lost lives [12]
[1] The planet is dangerously close to this climate threshold: What 1.5°C really means—Physorg, February, 2024
[2] Wildfires and Acres, National Interagency Fire Center, 2023
[3] Projected increases in western US forest fire despite growing fuel constraints—Communications earth & environment, November, 2021
[4] Wildfires in Europe burn area equivalent to one-fifth of Belgium—The Guardian, August, 2022
[5] United States Billion Dollar Disaster Events—National Centers for Environmental Information, 2023
[6] Study finds Western megadrought is the worst in 1,200 years—NPR, February, 2022
[7] China drought causes Yangtze to dry up, sparking shortage of hydropower—The Guardian, August, 2022
[8] It’s so hot, roads are buckling, they’re putting foil on a bridge and roofs are melting around the world—CNN, July, 2022
[9] Why Is Sea Level Rising Faster in Some Places Along the U.S. East Coast Than Others?—Woods Hole Oceanographic Institution, December, 2018
[10] As Sea Levels Rise in Boston, Stormwater May Have Nowhere To Go—WBUR, June, 2021
[11] Ice sheets can collapse at 600 metres a day, far faster than feared, study finds—The Guardian, April, 2023
[12] Atmospheric river lashes California with heavy rain and wind—CNN, February, 2024
[13] The Last Time CO2 Was This High, Humans Didn't Exist—Climate Central, May, 2013
[14] The Last Time CO2 Levels Were This High, There Were Trees at The South Pole—The Guardian, April, 2019
[15] A Graphical History of Atmospheric CO2 Levels Over Time—Earth.org, August, 2020
[16] A New 66 Million-Year History of Carbon Dioxide Offers Little Comfort for Today—Columbia Climate School, December, 2023
[18] Carbon Dioxide Fertilization Greening Earth, Study Finds—April, 2016
[17] What’s The Worst That Could Happen?—YouTube, WonderingMind, 2011
[19] New Panhandle wildfire emerges, forcing evacuation of tiny town of Sanford—The Texas Tribune