State of the climate: Summer 2021 sets new high for average land temperature

A growing La Niña.

The exceptional temperatures in 2021s summertime were not consistently hot. Some areas saw records shattered, while others were closer to typical– though a couple of regions also saw cooler-than-average temperature levels.

The figure below programs the temperature level abnormalities– modifications relative to the 1981-2010 average temperature– for each year considering that 1970, together with the average over the first nine months of 2021.

Hadley/UEA HadCRUT5 NASA GISTEMP NOAA GlobalTemp Berkeley Earth Copernicus/ECMWF.

May 9th8th6th8th5th.

Jul 4th2nd2nd3rd3rd.

The figure below shows summer season– June, July and August– temperature levels from the Berkeley Earth dataset in between 1850 and 2021. Each red dot represents the average temperature level over the 3 summer months..

Year-to-date temperatures for each month from 2013 to 2021 from NASA GISTEMP. Anomalies plotted with regard to a 1981-2010 baseline. Chart by Carbon Brief utilizing Highcharts.

Map of summer (June, July, August) average land surface area temperatures provided by Berkeley Earth.

The table below programs how each month in 2021 ranked across all the datasets taken a look at– with “2nd” showing the 2nd hottest temperature level on record for that month took place in 2021. Keep in mind that Hadley and Berkeley extend back to 1850, NASA and NOAA return to 1880, and Copernicus/ECMWF is only readily available given that 1979.

Apr 7th8th9th7th7th.

( Note: at the time of writing, September information was not yet offered for the Hadley/UEA or Berkeley Earth temperature records, so the average over the very first 8 months is revealed for those datasets.).

Aug 6th6th6th5th3rd.

Carbon Brief has evaluated records from six different research study groups that report international surface area temperature records: NASA; NOAA; Met Office Hadley Centre/UEA; Berkeley Earth; Cowtan and Way; and Copernicus/ECMWF..

Jun 6th3rd5th3rd5th.

The figure listed below shows a series of ENSO forecast models produced by different scientific groups, with the average for each model type shown by thick red, blue and green lines. Positive worths above 0.5 C show El Niño conditions, unfavorable values listed below -0.5 reflect La Niña conditions and values in between the 2 represent ENSO neutral conditions.

While international temperatures are an essential sign of climate modification, no human experiences the international average. Land areas have, typically, warmed around 50% faster than the world as an entire, with higher latitude land regions warming much faster still.

El Niño Southern Oscillation (ENSO) projection designs for three-month periods in the Niño3.4 region (March, April, May– MAM– and so on). Credit: CPC/IRI ENSO forecast..

This year will not set a brand-new international temperature record– but, even in a warming world, most individual years will not. Temperatures will end up around expected levels given the long-term warming trend over the past 50 years and follow projections from climate models.

The summer of 2021 saw extreme heat occasions, extreme rains and flooding, devastating wildfires and other severe occasions throughout the world. (These were gone over extensive in aCarbon Brief visitor post released last month.).

The results are revealed in the table listed below, with the possibility of the year ending up as the 5th, 6th or 7th hottest on record shown for each dataset. With data for the first three-quarters of the year in, there is virtually no chance that any of the surface temperature records will reveal 2021 as above the 5th warmest or listed below the 7th warmest year on record. At the time of publication, September 2021 data was not yet readily available for the HadCRUT5 or Berkeley Earth datasets.

February 2021 was unusually cool for the world as an entire compared to current years– clocking in at between the 12th and 16th warmest year on record. February was still warm compared to a lot of previous years, nevertheless– all however 15 or two years because records began in the mid-1800s had Februaries that were cooler.

Sep 2nd5th2nd.

The Northwestern part of North America, Eastern Europe, the Middle East, Northern Africa, and Siberia all experienced extremely warm summertime temperature levels. China, sub-Saharan Africa, South America and Australia were modestly above average, while parts of Central America and India were second-rate. (The average being specified as the 1951-1980 standard period used by Berkeley Earth).

The very first nine months of the year saw record concentrations of significant greenhouse gases– CO2, methane and nitrous oxide — in the environment. Arctic sea ice level was low for much of the year, but recovered in late summertime to set a minimum level on the 12th lowest on record..

Yearly international mean surface area temperature levels from NASA GISTEMP, NOAA GlobalTemp, Hadley/UEA HadCRUT5, Berkeley Earth and Copernicus/ECMWF (lines), together with 2021 temperatures to-date (January-September, coloured dots). Anomalies outlined with regard to a 1981-2010 standard. Chart by Carbon Brief utilizing Highcharts.

On track to be 5-7th hottest year on record.

Temperatures notably warmed by June 2021, with every month in between June and September being in between the 6th and 2nd warmest on record, though no months set a brand-new record in 2021 for the worldwide as a whole.

El Niño years tend to be warmer than average, while La Niña years tend to be cooler. When ENSO conditions peak in the tropical Pacific and when their impacts on international temperature levels are most strongly felt, there is typically a lag of around 3 months in between.

With data through to the end of the summer season now readily available, Carbon Brief can now confirm that the meteorological summer season of 2021 was the warmest summer on record for the worlds land areas– and the 4th hottest summer on record for the world as an entire (air, land and ocean).

Cooler than past couple of years– but still near-record warm.

Mar 9th7th8th9th9th.

The figure listed below programs how temperatures up until now in 2021 (black line) compare to prior years in the NASA GISTEMP dataset. It shows the temperature of the year-to-date for each month of the year, from January through to the full yearly average.

Utilizing the data from the very first nine months of the year, plus both past and forecast future ENSO conditions, Carbon Brief has produced a forecast of where 2021 temperatures will probably land for each various surface area temperature record..

El Niño and La Niñan occasions– collectively described as the El Niño Southern Oscillation, or ENSO– are the main driver of year-to-year variation on top of the long-term surface area warming trend. ENSO occasions are characterised by fluctuations in temperature level between the ocean and atmosphere in the tropical Pacific, which assist to make some years warmer and some cooler.

Hottest summertime on record for Earths acreage.

Receive our totally free Daily Briefing for an absorb of the past 24 hours of environment and energy media coverage, or our Weekly Briefing for a round-up of our content from the past 7 days. Simply enter your email below:.

As a whole, the world is on track to have its 5th to seventh warmest year on record– depending on the dataset examined and how the last three months of the year play out.

Feb 15th15th16th16th12th.

Hadley/UEA HadCRUT5 NASA GISTEMP NOAA GlobalTemp Berkeley Earth Copernicus/ECMWF.

The year so far has actually been one of extremes, including record-shattering heatwaves, wildfires and flooding, as well as the warmest-ever meteorological summer– June, July and August– in the global land-surface record..

The map below– from Berkeley Earth– reveals summer 2021 temperatures around the world.

Surface area temperature level records have actually shown around 1C warming given that the year 1970, a warming rate of about 0.19 C per decade. The outcomes differ a bit across datasets due to various observations used, adjustments for changes in measurement methods in time, and techniques used to fill out spaces in between measurements.

Rankings of 2021 temperature levels by month across various datasets.

Summer Season (June, July, August) average land surface temperature levels from Berkeley Earth. Abnormalities plotted with respect to a 1850-1900 baseline. Chart by Carbon Brief utilizing Highcharts.

Models now anticipate that modest-to-moderate La Niña conditions will persist through the very first quarter of 2022. This may result in 2022 being a bit cooler than the previous couple of years as well, though it is too early to know for sure.

Late 2020 and early 2021 saw moderate La Niña conditions that added to fairly cool international temperature levels in the early part of 2021. ENSO conditions were neutral for much of the spring and summer, before going back to modest La Niña conditions in September and October.

The year had a fairly cool start due to residues of a La Niñan event in late 2020 and early 2021. Warm land temperatures over the past few months have been cancelled by cooler ocean temperature levels as La Niña conditions have actually reappeared..

Summer land temperature levels were relatively flat up until 1975, with just around 0.2 C heating up to that point. Today, summertime land temperatures are around 1.5 C above pre-industrial levels, with around 1.3 C of that warming happening in just the previous 45 years.

So far, 2021 is tied for the 5th warmest to date with 2015 and 2018. It had a cooler start than those years, however warmer temperatures over the past few months have actually pressed year-to-date worths upwards. With a growing La Niñan event in the tropical Pacific, it stays to be seen whether temperature levels will remain fairly warm.

Jan 9th8th7th6th6th.

5th 0% 0% 72%.

Sixth 25% 79% 12%.

7th 75% 21% 16%.

Climate models provide physics-based estimates of future warming provided various assumptions about future emissions, greenhouse gas concentrations and other climate-influencing elements..

Twelve-month typical worldwide typical surface area temperatures from CMIP5 designs and observations in between 1970 and 2021. Designs utilize RCP4.5 forcings after 2005. They include sea surface temperatures over oceans and surface area air temperatures over land to match what is measured by observations. Abnormalities outlined with respect to a 1981-2010 standard. Chart by Carbon Brief using Highcharts.

While all three datasets produce comparable projections for 2021 annual temperature levels, there are slight differences that result in various rankings. This year is more than likely to be the 7th warmest on record in the NASA dataset, 6th hottest in NOAA and 5th warmest in Copernicus/ECMWF.

Annual global average surface temperature anomalies from Copernicus/ECMWF plotted with respect to a 1981-2010 baseline. To-date 2021 values include January-September. Approximated 2021 annual value based on relationship between the January-September temperatures and annual temperature levels between 1979 and 2020. Chart by Carbon Brief using Highcharts.

The figure listed below shows the series of private models forecasts included in the Intergovernmental Panel on Climate Changes (IPCC) fifth evaluation report– recognized collectively as the CMIP5 models — in between 1970 and 2030, with grey shading and the average projection across all the designs shown in black. Private observational temperature level records are represented by coloured lines.

Greenhouse gas concentrations reach record highs.

With monthly of extra data, the uncertainty in the anticipated 2021 yearly temperature level shrinks as there are fewer staying months to alter the average. The figure below illustrates this, revealing that both the very best price quote (red) and unpredictability range (black hairs) for 2021 yearly temperatures have changed over the course of the year as each additional month of data has actually become readily available..

Present temperature in-line with model projections.

Annual global mean surface temperature levels from Copernicus/ECMWF for 2016 (blue line), 2020 (black dot) and forecasts made in monthly of the year (black whiskers and red dots). Chart by Carbon Brief.

The figure below shows the 2021 to-date temperatures and annual 2021 projected temperatures (with unpredictabilities) for Copernicus/ECMWFs ERA5, along with the long-term temperature trend based upon data from 1979-2020. While 2021 temperature levels will be lower than much of the past few years, they are rather consistent with the longer-term warming pattern due to human emissions of CO2 and other greenhouse gasses.

Greenhouse gas concentrations reached a new high in 2021, driven by human emissions from fossil fuels, land use and agriculture..

In these designs, quotes of temperature levels prior to 2005 are a “hindcast” utilizing known past environment affects, while temperatures projected after 2005 are a “projection” based on an estimate of how things may change.

Approximated probabilities of 2021s temperature rank for each dataset, with the most likely outcome in bold. Note that these likelihoods do not consist of measurement unpredictability for each record, simply the very best price quote. Missing out on values represent datasets that have yet to report their September temperature levels. Once they are released, this post will be upgraded.

While international temperature levels were running a bit listed below the speed of warming projected by climate models between 2005 and 2014, the last couple of years have actually been pretty near to the design average. This is especially real for worldwide total temperature records, such as HadCRUT5, NASA, Berkeley Earth and the Copernicus/ECMWF reanalysis, that include temperature price quotes for the entire Arctic.

3 greenhouse gases– CO2, methane (CH4) and nitrous oxide (N2O)– are accountable for the bulk of additional heat caught by human activities. CO2 is by far the biggest factor, accounting for approximately 50% of the increase in “radiative requiring” because the year 1750. Methane accounts for 29%, while N2O accounts for around 5%. The staying 16% originates from other elements consisting of carbon monoxide gas, black carbon and halocarbons, such as CFCs.

Sharelines from this story.

Arctic sea-ice volume anomalies from 1979 through September 2021 from PIOMAS.

Global concentrations of CO2, methane (CH4) and nitrous oxide (N2O). Chart by Carbon Brief utilizing Highcharts.

Methodological note.

Arctic sea ice on low end of historic variety.

Human emissions of greenhouse gases have actually increased atmospheric concentrations of CO2, methane and laughing gas to their highest levels in a minimum of a few million years– if not longer..

An analytical multivariate regression design was utilized to estimate the variety of most likely 2021 annual temperature levels for each group that offers a temperature record. This model utilized the typical temperature over very first 9 months of the year, the most recent regular monthly temperature worth (September 2021), the typical ENSO 3.4 area worth throughout the very first 9 months of the year and the average forecasted ENSO 3.4 worth throughout the last three months of the year to approximate the annual temperatures. The model was trained on the relationship between these variables and annual temperature levels over the period from 1950 through 2020 (or 1979 through 2020 for the Copernicus/ECMWF reanalysis dataset). The model then utilizes this fit to predict both the most likely 2021 yearly value for each group, as well as the 95% confidence interval. The predicted ENSO 3.4 area worths for the last 3 months of 2021 are drawn from the NMME design indicate forecast.

The figure below shows concentrations of these greenhouse gases– in parts per million (ppm) for CO2 and parts per billion (ppb) for methane and laughing gas– from the early 1980s through July 2021 (the most recent information currently offered).

The summer season minimum– which typically happens in late September– was the 12th least expensive on record. Typical Arctic sea ice to-date (very first 289 days of the year) is the 9th most affordable on record. Antarctic sea ice degree was close to the long-term average over the very first 10 months of 2021..

Highly precise observations of Arctic and Antarctic sea ice have been available because polar-observing satellites appeared in the late 1970s. Arctic sea ice level was at incredibly low levels for much of the first half of 2021, setting new records in parts of both June and July..

Annual global mean surface area temperature levels from NASA GISTEMP, NOAA GlobalTemp, Hadley/UEA HadCRUT5, Berkeley Earth and Copernicus/ECMWF (lines), along with 2021 temperatures to-date (January-September, coloured dots). Approximated 2021 annual value based on relationship in between the January-September temperatures and annual temperatures between 1979 and 2020. They include sea surface area temperature levels over oceans and surface air temperatures over land to match what is measured by observations. A statistical multivariate regression model was used to approximate the range of likely 2021 yearly temperatures for each group that offers a temperature record. This design used the typical temperature level over very first 9 months of the year, the latest regular monthly temperature level worth (September 2021), the typical ENSO 3.4 area value during the very first nine months of the year and the average predicted ENSO 3.4 value throughout the last 3 months of the year to approximate the yearly temperatures.

The figure listed below, utilizing information from the Pan-Arctic Ice Ocean Modelling and Assimilation System (PIOMAS), reveals the Arctic sea ice density for each year between 1979 and 2021. There has been a clear down trend in sea ice volume over the past couple of years.

While there are some issues around modifications in the capability of the atmosphere to remove CH4 with time (through interactions with the OH particle), the increase in methane concentrations over the last few years highly recommends that global emissions of CH4 have actually likewise been increasing.

The atmospheric concentration of CH4 began to increase once again in 2006 after a plateau from 1999. It further accelerated since 2014, with roughly direct development of 8ppb each year since. Unlike CO2 and N2O, CH4 has a reasonably short atmospheric lifetime and does not build up in the atmosphere in the long term. This indicates that– to a very first approximation– the level of CH4 in the environment is straight proportional to the level of emissions over the past years.

The vibrant lines reveal everyday 2021 values, the shaded area shows the 2 basic discrepancy variety in historic worths in between 1979 and 2010. The dotted black lines show the record lows for each pole.

If emissions stay flat, climatic CH4 will be flat, while increasing emissions will appear as increased atmospheric CH4. If CO2 and N2O emissions stay flat, on the other hand, climatic concentrations would continue to increase.

The percent possibility of different year ranks for 2021 is estimated by utilizing the output of the regression design, assuming a regular circulation of results. This permits us to approximate what percent of possible 2021 annual worths fall above and below the temperature levels of previous years for each group.

The figure below shows both Arctic and Antarctic sea ice degree in 2021 (solid red and blue lines), the historical range in the record in between 1979 and 2010 (shaded locations) and the record lows (dotted black line). Unlike international temperature level records, sea ice information is gathered and updated daily, permitting sea ice level to be seen through to today.

Sea ice degree only informs part of the story. In addition to decreasing ice degree, the sea ice that remains tends to be more youthful and thinner than ice that used to cover the area..