What were the big energy and climate surprises of the Trump era? Four years ago, I described the most plausible arc for US climate policy under Trump (it was a boring, safe bet) but expected there'd be unexpected developments too. So how about a look back? https://t.co/1Valz4eTEg

Long thread here... from Keith, on tree guards:

I really don’t want to spread 120,000 plastic tree guards across the side of our lovely hill, the hill where I grew up and now farm, on the eastern edge of the Black Mountains. So, I’ve taken a good look at the pros,... 1/25

the cons and the alternatives, to try and decide rationally, which is the best approach for our plant on the Bryn Arw.

It has become the accepted norm in the UK that to plant a tree, you need to put your sapling in the ground and then wrap a plastic tree guard around it.

This is simply ‘how it’s done’ now. This practice uses a huge amount of plastic; worse still, it disperses plastic extremely efficiently around the countryside. In some rural places, un-retrieved tree guards are by far the biggest source of plastic pollution.

And yet the first commercial plastic tree guards only came on the market 38 years ago. There are many perfectly healthy woodlands and trees that are older than this, and which became established without plastic – which begs the question: do we really need guards?

Plastic tree guards have several uses, some of which did revolutionise tree planting when they first came out. In particular, they:
•protect your saplings from things that want to eat them;
•provide a microclimate, which enhances tree growth, according to the manufacturers;

Fascinating new paper by @AndrewDessler and colleagues arguing committed warming might be higher than expected given historical pattern effects. Its combining a lot of different concepts together, so lets spend some time disentangling them https://t.co/ILi5z515Qy

A thread: 1/19

The paper's headline number is that we previously thought the world was committed to 1.3C warming, but that number is actually over 2C (> 1.5C by 2100). This is quite a different message than we get from Earth System Models, which suggest committed warming is only ~1.2C. 2/19

This would imply that the 1.5C by 2100 target is effectively impossible, and that long-term warming of >2C would be very difficult to avoid. However, the devil is in the details, and the picture is not quite as dire as it would seem at first glance. 3/19

When we talk about "committed warming" folks are generally talking about one of two scenarios: either constant CO2 and other GHG concentrations (and forcings), or getting all emissions (or just CO2 emissions) down to zero immediately. 4/19

In the first method – constant concentrations – we find that the world warms up another 0.5C or so, as the oceans continue to take up heat as more energy is being trapped by greenhouse gases than is being emitted back to space. Much of this additional warming happens by 2100 5/19

Comparing two environmental regulation

Preventing emissions vs improving water quality,

Which one better?

https://t.co/zLrVNWIPXm

What is the Difference?
We certainly often hear the term better to prevent than cure. Of course, we all agree on that. But what about improving quality, is that better than preventing?

A researcher named Dan Pan tries to compare 2 different regulations on environmental impacts.

One of the regulations is based on environmental quality limits. the other is based on the market, but we will call it improving water quality because it gives reward and punishment on environmental performance.

Preventing Emissions:

• Restrictions or closings of companies that violate environmental quality standards

• Restricted areas must protect their water

• Implementing comprehensive water conservation

• Strengthens water recovery and protection

Improving water quality

Give awards to mayors whose evaluation scores are good, and adequate, whose evaluations are bad. There are several parameters defined in determining water quality such as: COD intensity, water quality, and industrial wastewater standards