I will suggest that both are profoundly wrong and that research is acutely needed to understand and project climate change forced by natural processes AND human-enhanced greenhouse gases. In this blog I will describe the importance of climate research and will discuss weaknesses in our understanding of human-caused climate change that are rarely admitted by scientists or discussed in the press. Weaknesses that must be addressed.
So why is climate research so important? Let me give you a few reasons.
Reason #1: The is Still Lots of Uncertainty of What Climate Change will Bring both Globally and Locally.
Both basic scientific principles (e.g., the physics of radiation) and our most comprehensive climate models strongly suggest the earth will warm as greenhouse gases increase. Importantly, as our global climate models get more and more complex, the uncertainty in their projections (the range of potential outcomes they suggest) has NOT CHANGED IN DECADES. Our best estimate are that a doubling of CO2 results in a range of roughly 1.5 to 4°C iincrease n global temperatures. We would have said the same thing 30 years ago.
Why so uncertain and haven't we become more confident? The list of reasons is a long one--here are just a few:
- Uncertainty in the amount of greenhouse gases there will be emitted and retained in the atmosphere.
- Uncertainty in how the land surface will change.
- Major uncertainties in model physics, such as how clouds form or how energy is exchanged with the surface.
- Inadequate resolution of the global models, making them unable to properly deal with topoography.
- Poor handling of convection/thunderstorms.
- Many global models fail to properly simulate natural variability, like El Nino/Nina and the MJO (Madden Julian Oscillation)....to name only few.
The uncertainty of the local impacts of global climate change is even larger than for global changes. Lack of resolution in global models means they don't properly handle local terrain, land-surface conditions, and land-water contrasts to name only a few factors that have huge impacts on local weather and climate.
To deal with local conditions, either the global climate models need far higher resolution or intense research/development into regional climate modeling is required, something a group of us is trying to initiate here in the Pacific Northwest.
Reason #2: Current climate climate models are "tuned" to reproduce the current climate and thus may have serious deficiencies. They may not be adequate for projecting future climate change.
A piece of dirty climate-change laundry is that our current climate models can not duplicate the current climate without "tuning" some parameters for which there are uncertainties. The fact we have to do this reveals that there are still deficiencies with our knowledge and/or ability to simulate the climate. Does this impact our ability to predict the implications of increasing greenhouse gases? We simply don't know.
Reason #3. There are many uncertainties in critical physical processes.
This reason is related to #1. How will a warming climate impact sea ice? Will large amounts of currently frozen methane be released? How have small particles (aerosols) changed over the past 100 years and how has this impacted the climate system? I could list dozens more of these: important processes we don't understand well, including how they will interact with a warming planet.
The bottom line is that our current climate modeling technologies have deficiencies, both on global and local scales. We have a lot to learn about basic physical processes that are critical for climate prediction. There is a huge amount of work for climate scientists, earth sciences, meteorologists, and oceanographers to work on. The science is not settled or certain other than there is little question that the planet will warm.
And society needs better answers from the scientific community for many reasons, including:
- To determine how serious the climate change threat from increasing greenhouse gases will be.
- To provide guidance on how society should adapt for future climate change, including construction of long-lived infrastructure
The U.S. will spend trillions of dollars on infrastructure (e.g., dams, roads, reservoirs, etc.), shouldn't decision makers have available the best possible information on what we expect to happen during the next century?
So even if you have your doubts about climate change (like Trump and some Republicans), doesn't it make sense to do the research needed to strengthen the underlying science and to reduce the uncertainties?
If you are one of the environmentally committed that have no doubt about the reality of climate change, isn't it prudent to get a better answer on what we expect will happen as the concentration of greenhouse gases increase?