Bjorn Lomborg Profile picture
Author of 'False Alarm', 'Cool It' and 'Skeptical Environmentalist', president Copenhagen Consensus think tank: smart solutions through economic prioritization
Leo Profile picture Mcrhoc Profile picture Louis Sufyerd Profile picture 没交稿吃土的🦉 Profile picture Thomas Greene Profile picture 11 added to My Authors
22 May 20
@JamesGDyke @past_is_future These are all great considerations, and we do discuss some of these as sensitivity

But given the incredible difference between the costs and benefits, it will be almost impossible to make the lockdown a good use of resources
@JamesGDyke @past_is_future I am surprised you would say "Your job is to show innaction & immediate deaths is "cheaper" than action"

That just wrong. We're trying to find what works best

I would encourage you to try to show other parameter choices that would show a lockdown is a great idea for Malawi
@JamesGDyke @past_is_future That would help the conversation forward, and also help Malawi (and Ghana and other countries)

And it would also be helpful to hear your reply to why it wouldn't be better first to help the people with HIV, where we can avoid more deaths at 4,000th the cost
Read 3 tweets
21 May 20
Even moderate lockdowns likely a terrible idea for poorer nations

We did a study with Malawi's National Planning Commission:

Lockdown avoids about 7,000 deaths but costs $12 billion

$3 million can avoid more deaths in Malawi (4,000 times cheaper)…
Imperial College finds that moderate social distancing reduces COVID death by about 12,000. We also expect less traffic deaths and less additional HIV death. Lockdown will also cause more malnutrition, tuberculosis and malaria, leading to a net benefit of 6,700 avoided deaths
The costs are: 1) shut down schools which leads to long-term lower child productivity. Since each extra school year increases wages by 12%, school lockdown cost is $5.2 billion (almost one year GDP) — the present value of income loss for 6 million children over the next
50 years
Read 11 tweets
20 May 20
World Economic Forum released its risk assessment for the coming 1.5 years:

All about recession & unemployment, economics and of course a second wave of corona…
Here is the full list of concerns for the next 1.5 years
No large environmental concerns — swamped by economic and others

Interestingly, World Economic Forum had over the past 15 years increasingly come to see the environment as the riskiest issue (here just months earlier)…
Read 4 tweets
23 Apr 20
Cost of Norway's corona school closure

The main cost is hidden: students will learn less, and be less productive in the coming decades

$160 lost per pupil per day

Total per day:
$137 million lost learning
$22 million lost parent productivity…
Each day, Norway produce $912m in GDP

Total school closure each day cost $159m

In total, more than 17% of daily GDP lost every day the schools are closed

(Norway GDP is 3.5 trillion NOK for 2019,…, or 9.7bn NOK per day)
Norwegian Institute of Public Health told government not to close schools, which could make corona more contagious.

The Prime Minister decided to close schools anyway because Denmark did so and pressure from local politicians……
Read 4 tweets
22 Apr 20
Many more people have died from corona, when looking at all deaths, not just public corona deaths

because of underreporting and people dying of other diseases while hospitals busy tackling corona

Great story from New York Times:…
Interestingly, the only country to accurately describe the number of corona deaths was Sweden…
The Economist has a similar article…
Read 5 tweets
20 Apr 20
Hard to keep people locked down:

In Norway:
1st week after lockdown 65% movement reduction
One month later, only 34% reduction

(based on mobile data,…)
This is why moderate distancing is a more plausible and sustainable long-term strategy

Moderate social distancing

- has more deaths in short run, but much fewer in long run

- is sustainable, because 1) people can live locked down like Sweden but not like Italy in long run; 2) long-run lockdown costs lower…
Read 4 tweets
16 Apr 20

Moderate social distancing is very smart

But often overlooked:

Too strict policies will actually lead to more overall critical illness and death

Too strict sees little infection, and then huge 2nd wave when restrictions lifted late August…
The Science paper explicitly points out that the most effective policy is "moderately effective social distancing"
Here is the same point from an idealized study on the Spanish Flu, designating the strict policy as "too effective"…
Read 6 tweets
16 Apr 20
Economic analysis from @ThunstromLinda and colleagues shows the benefits of social distancing outweigh the economic costs by $5.2 trillion

(Paper available here:…)…
This fundamentally tells us that doing *some social distancing* is better than doing nothing

I think this is correct — here is their basic illustration of cost paths

However, I'd like to highlight one major concern and some interesting points
The analysis ignores 2nd wave — what happens after we have successfully reduced infections in the first wave

It just assumes that there will be treatment or vaccine for the 2nd wave arriving in the fall

This could dramatically underestimate the cost of strong social distancing
Read 9 tweets
14 Apr 20
@RobRedmile We can get either, both or neither. Right now, lots of countries are locking down, ignoring long-run strategy

This could mean we end up with long lock-down, destroying economy, but then can't endure more lockdowns next fall etc, leading to both failed economy and many dead
@RobRedmile we could also do Sweden, which is moderate (but not no) cost, and likely imagine keeping this up for a long run, with moderate deaths
@RobRedmile (finally, notice that the strong lock-down as we saw in Italy and other places was probably necessary at the time, even if it might have been better to go to 'Sweden' precautions earlier)
Read 3 tweets
14 Apr 20
New Science study on corona shows that we might need social distancing into 2022 (either continuously or intermittently)

Such an approach is entirely unsustainable — it is impossible to imagine people being willing to accept that…
New Science paper:

*Strongest* lockdown *not* best. A really successful lockdown means almost no one gets infected in 1st wave, so the 2nd wave becomes almost as bad as not doing anything.

1st wave destroys economy
2nd wave kills just like doing nothing, just half year later
Of course, if you continue intermittent lockdown until 2022, you might avoid big death numbers, but eradicates economy.

Optimal approach is "moderately effective social distancing"

—Sweden approach: Keep infections<capacity, but allow transmission, so next wave much lower
Read 4 tweets
9 Apr 20
Norway has made a preliminary estimate of costs and benefits to go for long-term suppression vs transitioning towards a more Sweden-like approach.

Quick summary:
Short-term lock-down is better
Long-term Sweden-approach is better…
This is a quick study, so clearly not last word. The long-term suppression is six months, and then re-opening. The breaking-scenario (towards Sweden) envisions an opening back, accepting a much higher death rate (12,400 dead vs 199 dead) but much smaller long-term hit to economy
The study also includes extra health care costs from more infection but not extra costs from closed schools, less learning, more social stress etc.

The total cost difference is apparently 660B NOK, or $64B over 10 years (from table 2-7 and 4-2) — about $12K/person
Read 3 tweets
11 Dec 19
Bad climate policies proliferating:

Sweden to cut transport emissions by 70% in 2030

Will cost $5bn (1% GDP loss) per year by 2030 if done *most* effectively

Will cut 10.1MtCO₂e, so $500/tonne. Damage reduction is $31/t so

$1 will deliver 6¢ of climate benefits

1% of GDP by 2030 is government's own estimate…

Doesn't include transition costs + make a number of other, unrealistically optimistic estimates (like vastly increased biofuels won't lead to price hikes) p74

They even call this 1% cost 'relatively low' :)
GDP of $506bn in 2030 from SSP2…

10.1Mt from report, p8

Estimate of $31 across all SSPs and all damage functions, for 2030 from…
Read 5 tweets
10 Dec 19
Extreme weather not destroying more

Each climate conference day, we will look at the data

Flash flood is not worse:

Lower share of economy damaged by flash floods, not higher (because of more resilience)

From this new peer-reviewed article:…
Exactly what's found for floods and for mortality for all areas from last week
Some people have asked why the numbers only start in 1989 — it is because it is running 10-year averages (so 1989 is the average of 1980-1989).
Read 6 tweets
9 Dec 19
Extreme weather not destroying more

Each climate conference day, we will look at the data

Flooding is not worse:

Lower share of economy damaged by floods, not higher (because of more resilience)

From this new peer-reviewed article:…
This is exactly as we found for all extreme weather categories for mortality — lower, not higher — last week

Read 2 tweets
8 Dec 19
Extreme weather not killing more

Each climate conference day, we have looked at the data

Flooding is not worse:

Fewer people die from floods, not more (because of higher wealth and resilience)

From this new peer-reviewed article:…
And flash floods are not worse:

Fewer people die from flash floods, not more (because of higher wealth and resilience)

From this new peer-reviewed article:…
And coastal floods are not worse:

Fewer people die from coastal floods, not more (because of higher wealth and resilience)

From this new peer-reviewed article:…
Read 10 tweets
7 Dec 19
So, Denmark just passed its new climate law with everyone cheering

But no estimate of costs: Truth is, additional cost is 1-6% of GDP (>$120bn)

No estimates of benefits: Truth is, it will cut temperature in 2100 by a ten-thousandth of a degree Celsius

Nothing to celebrate
No official estimates. Costs estimated using Stanford Energy Modeling forum EMF28, and RICE

Temp benefit of 0.00001°C from UN standard estimate 1000GtCO₂=0.45°C, also from UN climate model MAGICC run……
Notice, this is only an estimate of the cost of the recent climate policies (i.e. going to 70% in 2030) and their increase in climate impacts,
here from my Danish article….
Read 3 tweets
5 Dec 19
Extreme weather not killing more

Each climate conference day, let's see the data

Today cold hazard:

Fewer people die from cold hazard, not more (because of higher wealth and resilience)

From this new peer-reviewed article:…
And tomorrow we'll see the heat wave impacts (also down!)
Everyone keeps saying extreme weather is having a greater impact. For every day of the climate conference, let's see how this is wrong
Read 3 tweets
30 Nov 19
There is just no end to the silly things blamed on climate

(My favorite is still the guy who thought climate change killed off the Loch Ness monster)…
Here is the guy, who stopped hunting for the Loch Ness monster, because it is now dead, a victim of global warming…
Read 2 tweets
16 Nov 19
The untruth that keeps coming back: global warming will be much costlier because of extreme weather: it will cost us 2.5%-7.5% just at 2°C…
Can we just realize that the global GDP cost of climate events has *decreased*, not increased
And is 'just' 0.26% down to 0.19%
graph updated from…
And that costs from pretty much *all* areas are declining across the world…
Read 6 tweets
5 Nov 19
You would imagine these 11,000 scientists at least were able to put together a coherent argument for why there is "an emergency"
They don't — they just ramble what seems like 1970s limits-to-growth thoughts
Read the paper
It is sad…
They show some graphs and literally worry about how people are being better off

The crucial graphs are just "linked at least in part to climate change"

Can't make this up
Compare scientists' concerns with people who are actually faced with the world's big problems

From the largest UN poll of global priorities: of almost 10m people, they — not surprisingly — care about education, health, jobs, no corruption and nutrition
Read 3 tweets
3 Nov 19
New York Times ran a sensational story on how many places will soon be underwater
it misuses data to conclude disaster, creating unreasonable fear…,
Now, let's get this clear:
1) Global warming is real, and
2) The research, they reference, looks good and useful, finding a better estimate for number of people potentially vulnerable to sea level rise…
Also kudos to Climate Central for making almost all of the data available online — here you can see at risk for flooding for 2050
(the only missing visualization is for 2020/today, as will become clear below)
They do include that info in academic article
Read 21 tweets