The Earth’s climate is a fragile natural system that is influenced by many factors; which can include: solar output, atmospheric greenhouse gas levels, Earth’s orbit, particulate matter concentrations, etc. Even small changes in any one of these inputs can have large ramifications for the climate, or the weather conditions prevailing in an area over a long period of time. Such changes can manifest themselves in many ways but one of the most responsive elements of the Earth’s climate is average global temperatures.
Throughout the millennia, Earth’s climate has changed numerous times, causing the planet to have relatively stable periods of average temperatures, phases of warming, and cooler periods that see large areas of the world become frozen under sheets of ice. Human civilization has developed during a period of relatively stable conditions where average global temperatures have allowed for centuries of productive agriculture, readily travel, and large swaths of usable land areas for development. One of the last great shifts in our climate was the Earth’s last ice age, which ended about 11,700 years ago. During this ice age, which saw ice sheets extend as far south as New York City, global average temperatures were about 11°F cooler compared to the twentieth century’s average of 56.7°F.
Today, the Earth’s climate is undergoing a period of accelerated warming (also known as global warming), and unlike previous instances of climate change that occurred due to natural factors, current observations are being caused by various human activities. Though warming has not been uniform across the planet, the upward trend in the globally averaged temperature shows that more areas are warming rather than cooling. According to the National Oceanic and Atmospheric Administration (NOAA) 2019 Global Climate Summary, the combined land and ocean temperature has increased at an average rate of 0.13°F per decade since 1880; however, the average rate of increase since 1981 (0.32°F) is more than twice as great. The 10 warmest years on record have all occurred since 1998, and 9 of the 10 have occurred since 2005. Looking back to 1988, a pattern emerges: except for 2011, as each new year is added to the historical record, it becomes one of the top 10 warmest on record at that time, but it is ultimately replaced as the “top ten” window shifts forward in time. To date, 2016 is the warmest year on record.
This web page is designed to serve as a factual education source for residents and visitors showcasing what is causing this current trend of warming, what effects this warming will bring, and mitigation solutions meant to reduce our influence on the planet’s climate and the changing climate’s effects on society. What you read here is only meant to serve as a basic overview of a very large and complex topic. We encourage you to use the links provided in the Additional Resources section of this web page to learn more.
Why is the Earth currently warming?
Today’s current trend of warming, which encompases an increase in surface, atmospheric, and oceanic temperatures, is attributed to increasing concentrations of greenhouse gases from human activities. What are greenhouse gases? Greenhouse gases are naturally occurring gases that contribute to the greenhouse effect, or the natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back into space and the rest is absorbed and re-radiated by greenhouse gases, allowing for our world to be habitable. Natural greenhouse gases include water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (NO), and ozone (O3). There are also synthetic greenhouse gases developed by humans that are extremely efficient at trapping heat in the atmosphere, including chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).
Since the Industrial Revolution, human activities – primarily the burning of fossil fuels like coal, oil, and natural gas, agricultural practices, and land clearing for development – have been artificially increasing the atmosphere’s greenhouse gas concentrations. This increase in concentrations is creating an enhanced greenhouse effect, leading to the warming trend currently being observed. In particular, these activities release large amounts of carbon dioxide and methane, some of the main excess greenhouse gases responsible for today’s warming due to their heat trapping efficiency.
Carbon dioxide is perhaps the most important of Earth’s long-lived greenhouse gases, having the ability to stay in the atmosphere as a molecule for centuries. In fact, carbon dioxide emissions from the first Ford Model T automobiles are still in the atmosphere. It absorbs less heat per molecule than gases like methane or nitrous oxide, but it is more abundant and it stays in the atmosphere much longer. Increases in atmospheric carbon dioxide are responsible for about two-thirds of the total energy imbalance that is causing the planet’s temperature to rise.
In 2019, the global average concentration of carbon dioxide was 409.8 parts per million (ppm). Simply put, this means that for every 1 million air molecules, roughly 409 of them are carbon dioxide molecules. For perspective, carbon dioxide concentrations were at roughly 280 ppm in 1750. The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases. It is estimated that carbon dioxide levels today are higher than at any point in at least the past 800,000 years. Between 1751 and 1990 (239 years), humanity is believed to have emitted 784 billion tons of carbon dioxide into the atmosphere. Between 1991 and 2019 (only 28 years), this increased to 831 billion tons.
At pace, carbon dioxide levels in the atmosphere could reach 900 ppm by 2100 and subsequently cause (along with other greenhouse gas increases) anywhere from 2.5°F to 10°F of further warming.
What effects will this warming cause?
Why does this even matter? How much difference could 2.5°F or 10°F really make? The short answer is: a lot.
Over the last several decades the effects of global warming have become increasingly apparent, but effects are disproportionate across the planet. Some regions have already seen significant changes while others are only just beginning to see impacts. For example, the Arctic is warming at twice the rate as the rest of the globe, leading to decreasing amounts of sea ice. Scientists are fairly certain of the consequences global warming will bring, but the severity and degree to which these impacts will be largely depends on whether or not we can reduce our emissions of excess greenhouse gases. Changes are already being observed, and there are certainly more to come.
The effects of global warming already being observed include but are not limited to:
- Average surface temperatures worldwide have risen by about 1.8°F since the pre-industrial era.
- Average global ocean temperatures have also risen. Sea surface temperature increased during the twentieth century and continues to rise. From 1901 through 2015, the ocean’s temperature rose at an average rate of 0.13°F per decade.
- Oceans are becoming more acidic due to increased amounts of carbon dioxide in the atmosphere. The world’s oceans naturally uptake carbon dioxide. In the last 200 years, the pH of surface ocean waters has fallen by 0.1 pH units. This might not sound like much, but the pH scale is logarithmic, so this change represents approximately a 30% increase in acidity.
- Terrestrial ice sheets and glaciers are melting. Terrestrial, or land ice sheets, and glaciers are decreasing in size all around the world. Some have unfortunately already disappeared. The pace of glacier loss has accelerated from -228 millimeters (9 inches) per year in the 1980s, to -443 millimeters (17 inches) per year in the 1990s, to -676 millimeters (2.2 feet) per year in the 2000s, to -921 millimeters (3 feet) per year for 2010–2018. The average annual loss of ice from Greenland and Antarctica in the 2010s was 475 billion metric tons – six times greater than the 81 billion metric tons a year lost in the 1990s. In total the two ice caps lost 6.4 billion metric tons of ice from 1992 to 2017, with melting in Greenland responsible for 60% of that figure.
- Polar sea ice is decreasing in coverage and thickness. Sea ice, or the ice that forms over the open waters of the Arctic and Antarctic, is declining due to warming temperatures, especially in the Arctic. Sea ice in the Arctic usually reaches its minimum extent each September during the end of the Northern Hemisphere’s summer. September Arctic sea ice is now declining at a rate of 13.1% per decade, relative to the 1981–2010 average.
- Sea levels are rising globally due to melting terrestrial ice sheets and glaciers. On average, global sea levels have risen 8–9 inches (21–24 centimeters) since 1880. The rate of sea level rise is accelerating, and has more than doubled from 0.06 inches (1.4 millimeters) per year throughout most of the twentieth century to 0.14 inches (3.6 millimeters) per year from 2006–2015.
- More intense weather patterns and storm systems are being recorded. The 2010s were the costliest decade on record in terms of global natural disasters, with direct economic damages totaling $2.98 trillion. This is $1.1 trillion higher than the 2000s, which saw $1.8 trillion in total damages. In 2019, the US alone saw 14 weather and climate related disaster events whose losses exceeded $1 billion, 7.5 events above the observed 1980–2019 average of 6.5 events per year. The annual US average of billion-dollar disaster events within the last 5 years is 13.8.
- Biodiversity losses are occurring. Due to temperature changes, animals are being forced out of their native habitats, or losing habitat altogether. Marine species such as coral are finding it difficult to adapt to more acidic oceans.
How do we slow down or reverse this warming?
At this point in time, warming will continue to occur for many decades due to the amount of heat trapping greenhouse gases already emitted into the atmosphere. This is especially true for carbon dioxide, which can remain in the atmosphere for centuries before breaking down.
However, we can still mitigate against even greater temperature increases and associated side effects in the future by reducing or eliminating our greenhouse gas emissions today where possible.
Slowing or even reversing the planet’s human-induced warming phase will not be achieved by any one solution. Instead policymakers, engineers, scientists, and everyday people from across the globe are working on multiple concepts, ideas, and technologies to reduce emissions. Low and zero carbon solutions and practices that are not only more environmentally friendly but also usually more resilient are emerging across socio-economic sectors in an effort to reduce human impacts on the climate.
This is why the City of Cape Canaveral is investigating, researching, and implementing forward thinking development practices that allow the municipality to reduce its own emissions while bolstering overall resilience against the challenges that will be caused by continued warming.
A few examples of low and zero carbon solutions involve the implementation of clean renewable energy that doesn’t utilize combustion to produce electricity, electrified vehicles that have little to no tailpipe emissions, reforestation efforts to regrow forest and other wilderness areas for the sequestration of carbon, and everyday small habit changes such as turning off lights when you leave a room or reducing your waste.
Such changes can help to alleviate future disaster related costs and also improve the health and wellbeing of residents and the natural environment within the Community by reducing harmful emissions. According to a report by the National Institute of Building Sciences, for every $1 spent on disaster mitigation projects, such as improving stormwater management systems or strengthening buildings against hurricanes, an average of $6 is saved on future relief costs. It is estimated that investment in low carbon technologies and measures within cities could cut global urban emissions by 90% by 2050 and would have a net present value of almost $24 trillion, equivalent to nearly one-third of the global GDP in 2018. This means that between now and 2050, the total benefits of these investments will exceed their total costs by almost $24 trillion. A recent study found that if the US replaced just 25% of internal combustion-engine automobiles currently on the road with electric vehicles (another zero emissions strategy) the country could save approximately $17 billion annually by avoiding damages from climate change and the healthcare costs of air pollution. More aggressive scenarios modeled – such as replacing 75% of US cars with electric vehicles – saw savings that could reach as much as $70 billion annually.
What do volcanoes have to do with climate change?
Overall, volcanoes release less than 2% of the equivalent amount of CO2 released by human activities. Quite small.
What's the difference between weather and climate?
“Weather” refers to the more local changes in the climate we see around us, on short timescales from minutes to hours to days to weeks. Examples are familiar – rain, snow, clouds, winds, thunderstorms, heat waves and floods. “Climate” refers to longer-term averages (they may be regional or global), and can be thought of as the weather averaged over several seasons, years or decades.
Do scientists agree on climate change?
Yes, the vast majority of actively publishing climate scientists – 97% – agree that humans are causing global warming and climate change.
What's the difference between climate change and global warming?
“Global warming” refers to the long-term warming of the planet. “Climate change” encompasses global warming, but refers to the broader range of changes that are happening to our planet, including rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times.
Is the Sun causing global warming?
No. The Sun can influence Earth’s climate, but it isn’t responsible for the warming trend we’ve seen over the past few decades.
What happens if the next solar cycle becomes less active? Will we go into a new ice age?
No. Even if the amount of radiation coming from the Sun were to decrease as it has before, it would not significantly affect the global warming coming from long-lived, human-emitted greenhouse gases. Further, given our greenhouse gas emissions to date and those expected to come, the evidence points to the next “ice age” being averted altogether.
What is the greenhouse effect?
The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.”
Why do most modern temperature records begin in 1880?
Three of the world’s most complete temperature tracking records – from NASA’s Goddard Institute for Space Studies, the National Oceanic and Atmospheric Administration’s National Climatic Data Center and the UK Meteorological Office’s Hadley Centre – begin in 1880. Prior to 1880, temperature measurements were made with instruments like thermometers. The oldest continuous temperature record is the Central England Temperature Data Series, which began in 1659, and the Hadley Centre has some measurements beginning in 1850, but there is too little data before 1880 for scientists to estimate average temperatures for the entire planet.
How are Earth's mountain glaciers faring in a warming world?
On average, most of Earth’s mountain glaciers are continuing to melt.
Has Earth continued to warm since 1998?
Yes, evidence shows warming from 1998 to the present, with the six most recent years (2014, 2015, 2016, 2017, 2018, and 2019) being the six warmest years globally since 1880.
Can you explain the urban heat island effect?
While urban areas are warmer than surrounding rural areas, the urban heat island effect has had little to no effect on our warming world, because scientists have accounted for it in their measurements.
Is the ozone hole causing climate change?
Yes and no. The ozone hole is not causing global warming, but it is affecting atmospheric circulation.
How do we know what greenhouse gas and temperature levels were in the distant past?
Ice cores are scientists’ best source for historical climate data. Other tools for learning about Earth’s ancient atmosphere include growth rings in trees, which keep a rough record of each growing season’s temperature, moisture and cloudiness going back about 2,000 years. Corals also form growth rings that provide information about temperature and nutrients in the tropical ocean. Other proxies, such as benthic cores, extend our knowledge of past climate back about a billion years into the past.
Are the land-based ice sheets in Greenland and Antarctica continuing to lose mass (ice)?
Data from NASA's GRACE satellites, which measured Earth’s gravity field, show that the land ice sheets in both Antarctica and Greenland have been losing mass (ice) since 2002.
How is Earth's sea ice faring in our warming world?
Arctic sea ice volume and extent have been declining since record-keeping began in the late 1970s and prior. Antarctic sea ice extent is currently below the long-term average of prior decades since 1979.
Is the ocean continuing to warm?
Yes, the ocean is continuing to warm. Notably, all ocean basins have been experiencing significant warming since 1998, with more heat being transferred deeper into the ocean since 1990.
Below are several additional resources residents and visitors can use to learn more about human-induced climate change and its effects.