Why climate modeling needs continuous updates

“Fifty years into the project of modeling Earth’s future climate, we still don’t really know what’s coming. Some places are warming with more ferocity than expected. Extreme events are taking scientists by surprise. Right now, as the bald reality of climate change bears down on human life, scientists are seeing more clearly the limits of our ability to predict the exact future we face. The coming decades may be far worse, and far weirder, than the best models anticipated… This is a problem. The world has warmed enough that city planners, public-health officials, insurance companies, farmers, and everyone else in the global economy want to know what’s coming next for their patch of the planet… Today’s climate models very accurately describe the broad strokes of Earth’s future. But warming has also now progressed enough that scientists are noticing unsettling mismatches between some of their predictions and real outcomes… Across places where a third of humanity lives, actual daily temperature records are outpacing model predictions… And a global jump in temperature that lasted from mid-2023 to this past June remains largely unexplained… Trees and land are major sinks for carbon emissions, and that this fact might change is not accounted for in climate models. But it is changing: Trees and land absorbed much less carbon than normal in 2023, according to research published last October… The interactions of the ice sheets with the oceans are also largely missing from models, Schmidt told me, despite the fact that melting ice could change ocean temperatures, which could have significant knock-on effects… The models may be underestimating future climate risks across several regions because of a yet-unclear limitation. And, Rohde said, underestimating risk is far more dangerous than overestimating it.” #ClimateRisk #TransitionRisk https://lnkd.in/eiSRvUeF

The challenges of climate change modeling: "The Earth is an unfathomably complex place, a nesting doll of systems within systems. Feedback loops among temperature, land, air, and water are made even more complicated by the fact that every place on Earth is a little different. Natural variability and human-driven warming further alter the rules that govern each of those fundamental interactions. On every continent except Antarctica, certain regions showed up as mysterious hot spots, suffering repeated heat waves worse than what any model could predict or explain. Across places where a third of humanity lives, actual daily temperature records are outpacing model predictions. And a global jump in temperature that lasted from mid-2023 to this past June remains largely unexplained. Per one researcher: “We have to approximate cloud formation because we don’t have the small scales necessary to resolve individual water droplets coming together." "Similarly, models approximate topography, because the scale at which mountain ranges undulate is smaller than the resolution of global climate models, which tend to represent Earth in, at best, 100-square-kilometer pixels. That resolution is good for understanding phenomena such as Arctic warming over decades. But “you can’t resolve a tornado worth anything.” "Models simply can’t function on the scale at which people live, because assessing the impact of current emissions on the future world requires hundreds of years of simulations. Some variables are missing from climate models entirely. Trees and land have been considered major sinks for carbon emissions. But it is changing: Trees and land absorbed much less carbon than normal in 2023. In Finland, forests have stopped absorbing the majority of the carbon they once did, and recently became a net source of emissions, which swamped all gains the country has made in cutting emissions from all other sectors since the early 1990s. The interactions of the ice sheets with the oceans are also largely missing from models. Changing ocean-temperature patterns are currently making climate modelers at NOAA rethink their models of El Niño and La Niña; the agency initially predicted that La Niña’s cooling powers would kick in much sooner than it now appears they will. "The models may be underestimating future climate risks across several regions because of a yet-unclear limitation. And underestimating risk is far more dangerous than overestimating it. Excerpts from The Atlantic article: Climate Models Can’t Explain What’s Happening to Earth Global warming is moving faster than the best models can keep a handle on. By Zoë Schlanger

Climate models rely on weak data for durable #CarbonRemoval, yet these same models shape today’s climate policy Most climate policy experts tend to focus on the #NDCs as the fundamental tool for creating political buy-in to scale up durable removals. But what informs the NDCs? The #IPCC reports. What informs the IPCC reports? The Integrated Assessment Models (IAMs). The IPCC’s Sixth Assessment Report (AR6) illustrates the problem well. Of the 121 model runs in AR6 scenarios aligned with “well below 2°C” and “above 1.5°C” pathways: 120 deployed BECCS, 28 (!) deployed DACCS None (!) represented biochar or ERW. Carbon Direct has just published an in-depth analysis of the problem and potential solutions. The narrow scope of novel and durable carbon removals in IAMs also shapes many countries' NDCs and long-term strategies. I'd add that there is another important element - the IPCC guidelines for the national greenhouse gas inventories (the GHG accounting rules for the governments), which have also suffered from the same shortcomings. It's great to learn that Carbon Direct is collaborating with three leading research institutions with well-established IAMs: Pacific Northwest National Laboratory, Utrecht University, and the International Institute for Applied Systems Analysis, to close this gap and represent removals more accurately in climate modelling: updating the latest cost assumptions, learning curves, and growth constraints for existing carbon removal technologies, while adding new representations of DACCS, biochar, and ERW. Have a look at their short blog post laying out the key issues: https://lnkd.in/eEczTaW2 There's a link to a longer white paper at the end of the blog. It's well worth the read!

"Taking into account all known factors, the planet warmed 0.2 °C more last year than climate scientists expected. More and better data are urgently needed." "..... 0.2 °C — a huge margin at the planetary scale..... Much of the world’s climate is driven by intricate, long-distance links — known as teleconnections — fuelled by sea and atmospheric currents. If their behaviour is in flux or markedly diverging from previous observations, we need to know about such changes in real time. We need answers for why 2023 turned out to be the warmest year in possibly the past 100,000 years. And we need them quickly." The planetary boundaries are pushed to tipping points faster than scientists expect. We need not only better data and more robust models, but also collective effective climate mitigation and adaptation measures, now. https://lnkd.in/gMBPXjsd Climate Governance Initiative The Climate Governance Initiative Hong Kong Chapter #sustainbility #climateaction #globalwarming #planet #climatescience