Creating successful seasonal forecasts may be the key to long-term climate change adaptation
The science of climate change is assessed every six or so years under the guidance of the Intergovernmental Panel on Climate Change (IPCC), which is divided into three working groups of which the first (WG1) assesses the status of climate science, the second (WG2) assesses the status of impacts, vulnerability and adaptation, while the third (WG3) assesses the status of actions to tackle climate change by mitigation as well as adaptation. The IPCC is currently reporting its sixth assessment report and the final report of WG1 was released last month.
The report, which has been prepared by 234 authors from 66 countries, is devastating news for the most climate-vulnerable countries. Climate change is now affecting every continent, region, and ocean on Earth, and every facet of the weather.
It states that humanity is changing the Earth’s climate rapidly and substantively leading to major, detrimental impacts which we must address.
The overall message is nothing new -- that temperatures are rising, and some effects are irreversible -- and wasn’t surprising. Those views are largely in line with its report in 2013, which we have known for decades. However, the report stated that it is not yet too late: Sea level rise can be restrained to survivable levels for small island states if the world respects the 1.5 degree Paris target.
If we miss the 1.5 degree target then we may see an eventual 3 metres of ocean rise which will drown the small island and vulnerable coastal nations. In a nutshell, this is a report on “less cause for panic, but more urgency to act.”
More interesting and potentially more significant is that “IPCC confirms that we must urgently shift the focus on to adaptation.” While mitigation is essential for long-term survival, adaptation determines whether we survive next week or next year when the deadly flood or hurricane strikes.
The IPCC is clear that the most intense tropical cyclones are increasing in intensity, and will continue to do so. Climate-driven disasters are happening already and are causing huge damage to every nation.
Despite the long-term warming signal, my understanding about the current climate problems are primarily centered on the disruptions due to the inter-annual climate variability and related temporal and spatial changes in rainfall, sea level, and tropical cyclones which, in other words, require a real-time response plan for adaptation.
I think this would be a better way to move forward. Once we learn how to adapt with a season-to-sub-seasonal climate crisis, we automatically gain resiliency to adapt with long-term climate problems. What is, therefore, needed is better comprehension of seasonal climate variability and change and improved translation of this information into products and their coordination to the ground level.
By definition, seasonal forecasts are forecasts of average seasonal conditions over a region that are made many months in advance due to slowly changing parts of the climate system. Analyzing ocean temperatures provides some ability to forecast average conditions for months in advance.
If it is possible to create successful seasonal forecasts, then generation of a probabilistic outlook of rainfall, flooding, and tropical cyclones is possible well ahead of seasons (3–6 months before the occurrence of flooding). The beauty of seasonal forecasting techniques is that it enables advance forecasts by at least 3–6 months.
In contrast to short-range deterministic climate forecasts (where we can generate information 3–7 days in advance), the probabilistic seasonal forecasts can produce information for about 3–6 months in advance with reasonable accuracy. However, while the deterministic forecasts are mostly accurate, due to their shorter time scales (hours to days), the probabilistic forecasts have some uncertainties because of their longer time scales (3–6 months).
To improve the forecast, the observed climate data and state of the science global datasets for other climate features could also be used. This information could help develop a strategy to address stakeholders’ needs through the climate response group.
Therefore, in addition to short-term deterministic forecasts, the medium-to-long term seasonal forecasts are essential in developing a real-time response plan for adaptation. This would significantly enhance the hazard management capability and agricultural decision support system in many highly climate vulnerable countries like Bangladesh.
Md Rashed Chowdhury is Adjunct Professor in the School of Sustainable Engineering and the Built Environment of Arizona State University, USA (Email: [email protected]).