Predicting Earth’s climate for the near future

The average temperatures worldwide will likely be higher in the upcoming five years than they have been in the past decades. This is one of the main results of a new report on climate predictions for the near future.

Yiguo Wang (NERSC), Francois Counillon (NERSC) and Noel Keenlyside (UoB/NERSC) have prepared the NorCPM simulations for the next five years used in the WMO report.Yiguo Wang (NERSC), Francois Counillon (NERSC) and Noel Keenlyside (UoB/NERSC) have prepared the NorCPM simulations for the next five years used in the WMO report.How will Earth’s surface temperature and other meteorological parameters likely change over the next five years? The World Meteorological Organization (WMO) has released the first “Global Annual to Decadal Climate Update” todaya report outlining climate predictions for 2020 and the near future, providing answers to this question. 

Researchers from the Bjerknes Centre for Climate Research (BCCR), Nansen Environmental and Remote Sensing Center (NERSC), and the University of Bergen (UiB) contributed to it. Bergen has always been an important part of the meteorological and climate research community, and this still holds true today.

 

Temperature increase twice as high in the Arctic

Excerpt of WMO report - Mean forecasts for both 2020-2024 and 2020, surface temperature changes compared to recent pastExcerpt of WMO report - Mean forecasts for both 2020-2024 and 2020, surface temperature changes compared to recent pastThe WMO report results are unsettling, but not unexpected: Compared to the recent past (defined as the 1981-2010 average), 2020 will likely see large land areas in the Northern Hemisphere experiencing temperatures of over 0,8 °C warmer than before.

Warming in the Arctic will likely be twice as much as the global mean. In fact, we have already seen this happen in 2020, with Siberia experiencing a record-breaking heat wave this spring and summer.

For the period 2020-2024, it is predicted that for almost everywhere on Earth, temperatures are likely to be warmer than in the recent past. 

Additionally, the report states that it is likely that the annual global temperature in each year until 2024 will be at least 1 °C warmer than it was before the industrialization during the 19th century. 

Sea-level pressure and precipitation are the other two parameters under investigation in the report, you can read about them at the WMO Lead Centre for Annual-to-Decadal Climate Prediction.

 

Combining climate models and observations

So, it is getting hotter, undeniably. But how have the researchers contributing to this report figured this out? How do such short-term climate predictions work?

To construct a coherent set of climate predictions for both the year 2020 and the period 2020-2024, ten different research centers worldwide provided input, each with their version of a climate model producing predictions for the near future. The different model outputs were compared and combined. 

This is an important distinction from standard climate projections, which only provide the sensitivity of our climate to external forcings (i.e. increasing CO2). Climate prediction additionally accounts for the predictable part of the natural climate variability. 

One of these ten research centers is the Bjerknes Climate Prediction Unit (BCPU) in Bergen. Noel Keenlyside (UiB/NERSC and leader of the BCPU), Yiguo Wang, François Counillon (NERSC) and Ingo Bethke (UiB) all contributed to producing the predictions for this report. They developed and utilized the Norwegian Climate Prediction Model (NorCPM), which combines the Norwegian Earth System model with the “advanced Ensemble Kalman Filter data assimilation” method, developed for ocean modelling at the Nansen Center over the last decades. Combining these fields of expertise it is possible to also optimize climate model predictions with observations. 

“Using the NorCPM with this special setup allows us to reduce the uncertainty in forecasting near future climate change. We can better predict the slowly varying components of the climate system. It is a new research field, and it bears huge potential”, says François Counillon. 

 

An emerging science

Climate prediction is a young branch of climate science and development is progressing rapidly. The accuracy of climate prediction will continue to improve into the future – similarly to the progress of weather forecasting in the past decades. Society today is extremely dependent on precise weather forecasts. In the future, predicting climate on short time scales such as years or decades may become just as important to each and every one of us.  

Climate prediction may bridge the gap between weather forecasts and long-term climate change projections. Another Bergen-based initiative, working in parallel to the BCPU, called “Climate Futures” is led by NORCE (partnering with NERSC and UiB, among others) and aims to address this gap. The project just received funding earlier this summer from the Research Council of Norway to become a Centre for Research-based innovation (SFI). 

Climate prediction is gaining more and more interest in society worldwide, and the WMO report just published is of crucial importance not just to researchers. 

BCPU leader Noel Keenlyside sums up its significance: “This first report is significant because it marks the recognition by the WMO of the importance of these outlooks for society. Such outlooks will become integral to decisions made by a wide range of private and public sector stakeholders and policy makers, and will contribute to the sustainable development of society.”

It is an exciting time in the field of short-term model-based climate prediction, and it is encouraging to know that Bergen researchers continue to work on the frontier of the unknown, just like past pioneers such as Bjerknes and Nansen. 

 

Also published in Norwegian at the Bjerknes Centre Varsler jordens klima på kort sikt.

NRK Nyheter Klimarapport varslar auka temperatur dei neste fem åra.

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