ENVIRONMENT

Carbon dioxide makes up 0.04% of the atmosphere by volume.

The portion of Earth's "greenhouse effect" caused by:

• carbon dioxide is 20%.
• water vapor is 50%.
• clouds is 25%.

According to NASA, "The rest is caused by small particles (aerosols) and minor greenhouse gases like methane."

According to a 2018 NOAA article, "Since 1750, the concentration of carbon dioxide in the atmosphere has risen 46 percent."

Per a NASA article, "According to an ongoing temperature analysis conducted by scientists at NASA’s Goddard Institute for Space Studies (GISS), the average global temperature on Earth has increased by a little more than 1° Celsius (2° Fahrenheit) since 1880."

"Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade," the article says.

According to David R. Henderson and Charles L. Hooper of Stanford University’s Hoover Institution, limitations of climate models include measurement error, imprecise estimates of the sun’s energy, cloud errors, and “discovered” inputs (those that are not produced by scientific studies).

Henderson and Hooper also note that the relationship between CO2 concentrations and temperature itself is complicated. "The glacial record shows geological periods with rising CO2 and global cooling and periods with low levels of atmospheric CO2 and global warming. Indeed, according to a 2001 article in Climate Research by astrophysicist and geoscientist Willie Soon and his colleagues, 'atmospheric CO2 tends to follow rather than lead temperature and biosphere changes,'" they say.

Further, “Climate models as a group have been 'running hot,' predicting about 2.2 times as much warming as actually occurred over 1998–2014. Of course, this doesn’t mean that no warming is occurring, but, rather, that the models’ forecasts were exaggerated."

Per a paper published in the Journal of Geophysical Research, “A definitive assessment of uncertainties is impossible, because it is always possible that some unknown error has contaminated the data, and no quantitative allowance can be made for such unknowns.”

According to the International Energy Agency, "The United States saw the largest decline in energy-related CO2 emissions in 2019 on a country basis – a fall of 140 Mt, or 2.9%, to 4.8 Gt. US emissions are now down almost 1 Gt from their peak in the year 2000, the largest absolute decline by any country over that period."

" Emissions outside advanced economies grew by close to 400 Mt in 2019, with almost 80% of the increase coming from Asia," the Agency notes.

According to NASA, there was a 25 percent decrease in the global land area burned by fires from 2003 to 2019. 

According to a 2014 NASA article,

"[T]ropical forests may be absorbing far more carbon dioxide than many scientists thought, in response to rising atmospheric levels of the greenhouse gas. The study estimates that tropical forests absorb 1.4 billion metric tons of carbon dioxide out of a total global absorption of 2.5 billion -- more than is absorbed by forests in Canada, Siberia and other northern regions, called boreal forests."

According to a 2015 NASA analysis of satellite data, "The Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008."

A 2007 paper published in Geophysical Research Letters found, "The emerging pattern of tropospheric temperature changes shows that large cooling in the summer and fall seasons largely compensates the warming during the winter and spring seasons so that the annual mean trend is small."

A 2006 paper in the Journal of Climate revealed that glaciers decayed and retreated in the eastern Himalayas from 1961 to 2000. 

However, in the western Himalayas, glaciers thickened and expanded.

A 2011 paper published in the Journal of Coastal Research found “small average sea-level decelerations” during the 20th century—a result “consistent with a number of earlier studies of worldwide-gauge records.”

An article published in Nature Climate Change in 2016 found “a persistent and widespread increase” in greening “over 25% to 50% of the global vegetated area” during 1982-2014.

On the other hand, “[L]ess than 4% of the globe” showed browning.

The results showed that "CO2 fertilization effects explain 70% of the observed greening trend."

An article published in Nature in 2018 analyzed "35 years' worth of satellite data" to “provide a comprehensive record of global land-change dynamics during the period 1982-2016.”

It found that tree cover increased by 7.1%.

According to the article, "This overall net gain is the result of a net loss in the tropics being outweighed by a net gain in the extratropics."

For context, 1.2 million species have been catalogued, but "some 86% of existing species on Earth and 91% of species in the ocean still await description," according to an article in PLOS Biology.

Per the International Union for Conservation of Nature (IUCN), “At least 27 species are recorded as having become Extinct or Extinct in the Wild during the last 20 years (1984–2004) (Tables 3.2 and 3.3).”

Per a paper published in Science in 2015, “The International Union for Conservation of Nature (IUCN) records only 15 global extinctions of marine animal species in the past 514 years (i.e., limit of IUCN temporal coverage) and none in the past five decades.”

A paper published in Diversity and Distributions in 2012 found, “Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands.”

A paper published in Global and Planetary Change in 2010 analyzed "physical changes in 27 atoll islands in the central Pacific over a 19 to 61 yr period."

The paper found that “86% of islands remained stable (43%) or increased in area (43%) over the timeframe of analysis.”

“Only 14% of study islands exhibited a net reduction in island area," the paper says.

A later (2018) reanalysis of available data, "which cover 30 Pacific and Indian Ocean atolls including 709 islands, reveals that no atoll lost land area and that 88.6% of islands were either stable or increased in area, while only 11.4% contracted."

Research published in Nature Climate Change in 2016 found, "Earth's surface gained 115,000 km2 of water and 173,000 km2 of land over the past 30 years, including 20,135 km2 of water and 33,700 km2 of land in coastal areas."

A paper published in the Hydrological Sciences Journal in 2012 explored statistical relationships between "annual floods at 200 long-term (85–127 years of record) streamgauges in the coterminous United States and the global mean carbon dioxide concentration (GMCO2) record."

"In none of the four regions defined in this study is there strong statistical evidence for flood magnitudes increasing with increasing GMCO2," the paper found.

In fact, "One region, the southwest, showed a statistically significant negative relationship between GMCO2 and flood magnitudes."

A paper published in the Journal of Hydrology in 2015 studied “precipitation measurements made at nearly 1000 stations located in 114 countries."

The paper found “no significant global precipitation change from 1850 to present.”

A 2000 paper published in Weather and Forecasting analyzed economic damages from tornadoes in the U.S. over the period 1890–1999 and concluded that “roughly the same number of high-damage tornadoes is found from 1970-1999 and prior to 1930."

Researchers concluded that there is “nothing to suggest that damage from individual tornadoes has increased through time, except as a result of the increasing cost of goods and accumulation of wealth of the US.”

A paper published in Environmental Hazards in 2013 estimated the economic damages from tornadoes in the U.S. from 1950 to 2011 and found “a sharp decline in tornado damage” after normalizing “for changes in inflation and wealth at the national level and changes in population, income and housing units at the county level.”

A paper published in Natural Hazards in 2008 studied economic damages from hurricanes in the U.S. from 1900 to 2005 and found “no remaining trend of increasing absolute damage in the data set” after normalizing the data for changes in population, housing units, inflation, and wealth.

A paper published in Nature Sustainability in 2018 studied economic damages from hurricanes in the U.S. from 1900 to 2017 and found “no trend” in economic losses after normalizing the data.

In fact, “The greatest annual normalized damage occurred in 1926 (US $244 billion), exceeding the next greatest loss year (2005) by about US $74 billion," the paper says.

A 2016 analysis of natural disasters worldwide found, "The absolute total of deaths through natural catastrophes has remained reasonably constant with a slight decrease. Around 50,000 people on average die each year. However, relative to population, death tolls have decreased significantly from 1900-2015."

Unlike previous research that used climate models to study changes in areas under drought, a paper published in the journal Theoretical and Applied Climatology in 2014 used global satellite observations and found “no significant trend in the areas under drought over land in the past three decades.”