But — not all parts of it are heating up at the same rate. Temperature in the Arctic in particular is rising faster than the global average. The Arctic, according to NASA data, warmed by about 2.2 °C (4 °F) between 1900 and 2015.

Their estimate of Arctic heating is considerably bigger than NASA's. It indicates that between 1900 and 2015, Arctic temperature has risen about 2.9 °C (5.3 °F).

Change in average surface temperature (1986-2005 and 2081-2100)

The oceans have a huge thermal mass compared to the atmosphere and land surface. They act as the planet’s heat storage and transportation system, as the ocean currents redistribute the heat. This is important because if we look at the global surface temperature as an indication of warming, we’re only getting some of the picture. The oceans act as a huge storage heater, and will continue to warm up the lower atmosphere (no matter what changes we make to the atmosphere in the future).

“Charney 1979 Climate Senstivity” is about 3oC for a doubling of CO2. The range shown is for climate sensitivities of 1.5 to 4.5.

Newer studies use different types of scenarios, called Representative Concentration Pathways (RCPs), to predict future climate change. Climate models using the highest of these new concentration pathways, called RCP8.5, suggests four degrees warming as a best estimate for a world scenario where little or no mitigation action is taken.

This shows estimates of global average surface air temperature over the ~540 My of the Phanerozoic, since the first major proliferation of complex life forms on our planet. A substantial achievement of the last 30 years of climate science has been the production of a large set of actual measurements of temperature history (from physical proxies), replacing much of the earlier geological induction (i.e. informed guesses). The graph shows selected proxy temperature estimates, which are detailed below. Because many proxy temperature reconstructions indicate local, not global, temperature -- or ocean, not air, temperature -- substantial approximation may be involved in deriving these global temperature estimates. As a result, the relativities of some of the plotted estimates are approximate, particularly the early ones.

Global surface air temperature anomalies relative to 1951-1980 base period for annual and 5-year running means. Green vertical bars are 2s error estimates (Hansen et al. 2010).

Global average temperature is one of the most-cited indicators of global climate change, and shows an increase of approximately 1.4°F since the early 20th Century. The global surface temperature is based on air temperature data over land and sea-surface temperatures observed from ships, buoys and satellites. There is a clear long-term global warming trend, while each individual year does not always show a temperature increase relative to the previous year, and some years show greater changes than others. These year-to-year fluctuations in temperature are due to natural processes, such as the effects of El Ninos, La Ninas, and the eruption of large volcanoes. Notably, the 20 warmest years have all occurred since 1981, and the 10 warmest have all occurred in the past 12 years.

The globe as a whole warmed by about 1.1 °C (2 °F) between 1900 and 2015.

There aren’t that many full-blown El Niño events, but global temperatures during El Niños seem to be following a steady upward trend. There are more La Niña events, and those global temperatures also clearly follow a steady upward trend. Finally, the temperatures during the many neutral years also show no sign of departing from a steady upward trend. There’s enough scatter in the neutral years that if one had considered the period 1977-1987, or the period 1987-1997, one might be tempted to say that the neutral years had little or no warming. But the past decade fits nicely with the long-term upward trend of 0.16 C/decade shown by all three time series.

Some questions about the role of ENSO in setting records in annual s. We know the El Niño warms the global mean, La Niña cools it, but what happens when statistically correct for that?

Climate change projected by the IPCC 2013 report under the business as usual scenario (RCP8.5) projects climate change in the next 100 years to be as big as the Paleocene/Eocene Thermal Maximum extinction event 56 million years ago. Changes today however are happening 100 times faster than the PETM. The PETM was likely a methane clathrate melt event where frozen methane (natural gas) on the ocean floor melted. The event happened over a time period of about 10,000 to 20,000 years and resulted in an extinction event centered on the world’s oceans. Nearly half of all life in the oceans perished as the methane melt increased ocean acidity beyond the threshold of life for those organisms. Ten million years before the PETM, a giant asteroid hit the Yucatan Peninsula and the dinosaurs, along with 75% of life on Earth, went extinct. Since the asteroid impact, mankind’s climate change stands alone. The dinosaur extinction event is difficult to compare with what is happening today. What happened 65 million years ago? That 6 mile wide asteroid blew out a crater 110 miles wide and threw enough dust in the atmosphere to block the sun for a year and photosynthesis failed. The red-hot ejecta from the impact fell back to Earth and burned most of the planet. What didn’t die during this cataclysm died from climate change caused by the massive increase in atmospheric carbon from vaporized rock and global fires. So climate change today is second in severity in the last 65 million years only to this extinction event which was the worst in 250 million years.

Yes. Earth’s average surface air temperature has increased by about 0.8 °C (1.4 °F) since 1900, with much of this increase taking place since the mid-1970s (figure 1a). A wide range of other observations (such as reduced Arctic sea ice extent and increased ocean heat content) and indications from the natural world (such as poleward shifts of temperature-sensitive species of fish, mammals, insects, etc.) together provide incontrovertible evidence of planetary-scale warming.

Figure 2.20. Change in surface air temperature at the end of this century (2081-2100) relative to the turn of the last century (1986-2005) on the coldest and hottest days under a scenario that assumes a rapid reduction in heat trapping gases (RCP 2.6) and a scenario that assumes continued increases in these gases (RCP 8.5). This figure shows estimated changes in the average temperature of the hottest and coldest days in each 20-year period. In other words, the hottest days will get even hotter, and the coldest days will be less cold. (Figure source: NOAA NCDC / CICS-NC).

Amazingly, sea level has regularly cycled up and down about 120 meters, or almost 400 feet on a regular cycle, pretty much every 100,000 years. That has been going on for at least 2.7 million years. - See more at: http://www.johnenglander.net/sea-level-rise-blog/why-sea-level-will-rise-centuries-ultimately-100-feet

The average surface temperature of the world's oceans has been increasing since about 1910.

Figure 2.3. Observed global average changes (black line), model simulations using only changes in natural factors (solar and volcanic) in green, and model simulations with the addition of human-induced emissions (blue). Climate changes since 1950 cannot be explained by natural factors or variability, and can only be explained by human factors. (Figure source: adapted from Huber and Knutti29).

The climate curve looks like a “hump”. At the beginning of the Holocene – after the end of the last Ice Age – global temperature increased, and subsequently it decreased again by 0.7 ° C over the past 5000 years. The well-known transition from the relatively warm Medieval into the “little ice age” turns out to be part of a much longer-term cooling, which ended abruptly with the rapid warming of the 20th Century. Within a hundred years, the cooling of the previous 5000 years was undone. - Click here for more information

1.       “ Anders Levermann et al, June 2013 PNAS

Global  is rapidly approaching the 1.5°C Paris target. In the absence of external cooling influences, such as volcanic eruptions,  projections are centered on a breaching of the 1.5°C target, relative to 1850-1900, before 2029. The phase of the Interdecadal Pacific Oscillation (IPO) will regulate the rate at which mean  approaches the 1.5°C level. A transition to the positive phase of the IPO would lead to a projected exceedance of the target centered around 2026. If the Pacific Ocean remains in its negative decadal phase, the target will be reached around 5 years later, in 2031. Given the temporary slowdown in global warming between 2000 and 2014, and recent initialized decadal predictions suggestive of a turnaround in the IPO, a sustained period of rapid  rise might be underway. In that case, the world will reach the 1.5°C level of warming several years sooner than if the negative IPO phase persists.

Surface temperatures averaged across the U.S. have also risen. While the U.S. temperature makes up only part of the global temperature, the rise over a large area is not inconsistent with expectations in a warming planet. Because the U.S. is just a fraction of the planet, it is subject to more year-to-year variability than the planet as a whole. This is evident in the U.S. temperature trace.

Climate Facts

Temperature


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El Niño/La Niña Global Surface Temperature Influence - 1967-2012
Snce El Nino and La Nina have such an impact on global atmospheric temperatures, the best way to look at the atmospheric temperature change is to categorize the global temperature by “type of year”, which indicates that the atmospheric temperatures have been increasing at the same steady rate (about .16°C /decade) since 1970
Energy absorbed by the Earth 1970-2010 - Most of the heat is going into the oceans
As a result of the increase in atmospheric CO2, the Earth has been absorbing an excess of about 8 zeta joules of energy/year (the equivalent of a 50 megaton nuclear bomb being exploded every 15 minutes), with almost all of the energy going in to warming the oceans.
Global Land-Ocean Temperature Index - 1880-2011
The Earth’s average temperature has increased about .8°C (1.4 °F) since pre-industrial times
Trajectories toward the 1.5°C Paris target: Modulation by the Interdecadal Pacific Oscillation
Global  is rapidly approaching the 1.5°C Paris target. In the absence of external cooling influences, such as volcanic eruptions,  projections are centered on a breaching of the 1.5°C target, relative to 1850-1900, before 2029. The phase of the Interdecadal Pacific Oscillation (IPO) will regulate the rate at which mean  approaches the 1.5°C level. A transition to the positive phase of the IPO would lead to a projected exceedance of the target centered around 2026. If the Pacific Ocean remains in its negative decadal phase, the target will be reached around 5 years later, in 2031. Given the temporary slowdown in global warming between 2000 and 2014, and recent initialized decadal predictions suggestive of a turnaround in the IPO, a sustained period of rapid  rise might be underway. In that case, the world will reach the 1.5°C level of warming several years sooner than if the negative IPO phase persists.