Thread by @BjornLomborg

Heatwave magnitude in the US was highest in the 1930s

How do we know? Follow the science:

It is the conclusion from the US Fourth National Climate Assessment "heat wave magnitude reached a maximum in the 1930s."

science2017.globalchange.gov/downloads/CSSR… p191

Heatwave magnitude in the US was highest in the 1930s

How do we know? Follow the science:

EPA has one — and only one — century-long heat wave indicator. It shows heatwaves strongest in 1930s decade and maxed in 1936

epa.gov/climate-indica…

The official climate information of the US government tells us that over the last century, US heatwaves peaked in the 1930s

This is incontrovertible

But some don't like this information

Climate scientist Dessler argues "that just doesn't look right"

Instead of using US Climate Assessment and EPA, Dessler makes his own graph

Ostensibly it relates to heatwaves, but actually shows number of warm days

1. that's not heatwaves
2. that's not using any of the official measures for heatwaves

Since so many seem eager to believe Dessler's graph

let's just dissect it:

Dessler says he's graphing hot days

But HadEX3 (temp data used for IPCC) actually shows *the opposite* result (with 1930s max)

agupubs.onlinelibrary.wiley.com/doi/abs/10.102…

So Dessler feels that the data from US National Climate Assessment and EPA "just doesn't look right"

makes up a graph that doesn't show heatwaves but hot days

and his graph doesn't match other data

climdex.org/access/,

Dessler claims his new graph shows "heatwaves are certainly worse today than in the 20th century"

Yet, his data doesn't show heatwaves, doesn't match verified data, and conflicts with official findings of US Climate Assessment and EPA

tl;dr: Implausible

To me, the most astounding part:

why would so many cheer Dessler's poor performance against the best science?

Could it be that scary stories are more important to many than following the best science?

Dessler claims that I cherry-pick in two ways:

1. I pick an "unusual metric"

Really? I use the metric chosen by EPA and the two metrics chosen by US Climate Assessment

No, Dessler,

cherry-picking is making up your own graph, badly

Dessler claims that I cherry-pick in two ways:

2. I only look at the US

That is just silly. So the entire US Climate Assessment, which only looks at the US is cherry-picked?

Of course, the US is a relevant topic.

After I engaged with Dessler, he produced multi-day graphs (thx)

But still vague (he says min, but insist max), don't replicate EPA and US Climate Assessment

and not replicated by HadEX3 (IPCC)

Just to clarify:

Climate change is real, man-made+problem

Carbon taxes+green innovation smart

Globally and future, heatwaves will increase, coldwaves decrease

But scaring us witless with bad information is unlikely to lead to smart policies

Addendum on data concerns: Smart researchers at NCA+EPA *know* about limitations and take them into account

Exactly the reason for assessments — so we know what's correct w/all caveats considered

EPA: "not sufficient to change trends"

h/t @SlagOffTwits
epa.gov/climate-indica…