Thread by @edgarrmcgregor

This is Paradise, California at 9:30 AM this morning. People are in traffic fleeing from a wildfire. The sun is completely blocked out by smoke.

This is NOT the new normal in California because this will continue to get worse in the years to come.

Lets discuss why 1/

https://twitter.com/glenncanon/status/1060587358632914944

Wildfires need 3 things to become massive infernos:

- Lots of dry fuel
- High winds
- Low humidity

I will be discussing each one and how they are changing to make wildfires both hotter and bigger in California.

1. Dry Fuel

Many may think that with less rain, plants would be less abundant and less "fuel" would grow in the first place. While California is drying out, rain still falls heavily during the winter. According to NOAA, annual average rainfall ranges between just 3 inches

in the desert portions of the state to nearly 70 inches in the northern parts of the state. This allows lots of plants, grasses and trees to grow throughout the state. Here is the problem; Most of this rain only falls in 5 months out of the year (Nov-Mar) in most of the state,

except the deserts which recieve monsoon rain in summer. Because most of the year is dry in California, repeated windstorms and heatwaves can dry out these plants, grasses and trees, providing fuel for wildfires. Even worse, worsening droughts are providing fires with large,

dead trees. According to the US Forest Service, more than 100,000,000 trees died between 2012 and 2016 due to the combined efforts of droughts and bug infestations. All of these dead trees are exactly what wildfires need to explode in fury.

2. High winds

Foehn winds in California are often blamed on some of the worst wildfires in state history. These winds are better known as the Santa Anas in the south and the Diablo winds in the northern part of the state. These winds are generated immediantly

after a trough has passed through state and moves into Arizona. Meanwhile, high pressure builds in the Great Basin and creates strong gradients between the coasts and the Great Basin. This gradient, difference in pressure between 2 locations, relaxes itself by moving

air from the high pressure rotating outwards into the low pressure rotating inwards. As a result, air is forced through mountain passes and canyons as it accelerates and heats up. These winds are perfect for wildfires

as they can push embers well ahead of the front of the fire. However, climate change is making these worse too.

According to Norman Willer, a professor at the school of Geography at UC Berkely, these winds are becoming more common and stronger. Here is how:

The speed and strength of the jet stream depends on a difference of temperature between the poles and the equator. Climate change is warming the poles much more quickly than the equator, reducing this difference. As a result, the jet stream weakens and is more subject to meander.

As a result, high pressure systems form more often in locations that they like, such as the Great Basin. The setup for Santa Ana and Diablo winds is occuring more often, increasing the frequency of these events. These winds are getting worse.

3. Humidity

As Santa Ana winds become more frequent, periods of low humidity will aswell. Low humidity allows heatwaves to evaporate moisture inside plants, allowing them to burn more easily.

So the fuel, the winds and the humidity are all worsening in California. To nobodies surprise, so are the occurences and fury of wildfires.

These wildfires WILL get worse and worse. We can continue to ignore climate change, but that won't stop it from biting us in the ass.

We need to educate ourselves on climate change. We need to vote out politicans who refuse to address this issue. We cannot afford to wait any longer.

Unroll @threadreaderapp