Comment by twelfthnight | Hacker News Reader

Comment by twelfthnight | Hacker News Reader

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This reference agrees with you in the short/mid term (to your credit, which you explicitly mention), but states in the long term climate change is the most important factor, regardless of demand. Taking action against alfalfa is a sensible thing to do right away, but won't address the looming crisis:

> In the near-term (2012 through 2026), water demands are similar across scenarios, and the largest factor affecting the system reliability is water supply. In the mid-term (2027 through 2040), the demand for water is an increasingly important element in the reliability of the system, as are assumptions regarding the operations of Lakes Powell and Mead. In the long-term (2041 through 2060), the futures that consider the Downscaled GCM Projected water supply scenario, which incorporates projections of future climate, show a high inability to meet resource needs, regardless of the demand scenario and the operation of Lakes Powell and Mead. "

Serious question: Have climate scientists previously been able to accurately predict climate changes decades away on a regional basis?

Not an expert but here's what I found from a little research:

It's hard to quantify, but it does seem like regional predictions are less accurate than continental, and predictions about rainfall are less accurate than temperature. However, predictions of rising temperature are essentially guaranteed.

> There is considerable confidence that climate models provide credible quantitative estimates of future climate change, particularly at continental scales and above ...

> Confidence in model estimates is higher for some climate variables (e.g., temperature) than for others (e.g., precipitation).

> Over several decades of development, models have consistently provided a robust and unambiguous picture of significant climate warming

Sources:

[1] https://oceanservice.noaa.gov/education/pd/climate/factsheet... [2] https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/faq...

In terms of temperature, yes. Early climate models correctly predicted that warming would be concentrated at the poles, for example:

https://en.wikipedia.org/wiki/History_of_climate_change_scie...

>Also in 1969, Mikhail Budyko published a theory on the ice–albedo feedback, a foundational element of what is today known as Arctic amplification.

This is generally confirmed by observations, as seen in the graph:

https://en.wikipedia.org/wiki/Polar_amplification

I assume four decades should be enough. I don't know about precipitation modeling, that stuff's really hard and the variance is huge.

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