Thread by @NiwaWeather

The highest concentration of sulfur dioxide (SO2) in the world right now is over the Pacific 📈

This is associated with the eruption of the Hunga-Tonga-Hunga-Ha'apai volcano 🌋

🧵 on what this means...

Some of the SO2 has been wrapped into Cyclone Cody, east of New Zealand 🌀

This is happening in the troposphere, the part of the atmosphere where we live.

Here, the emissions from volcanic eruptions are typically washed away quickly.

What matters to global climate 👉 how much SO2 has reached the stratosphere?

There, SO2 is converted to sulfuric acid droplets over a few weeks.

These aerosols can have a long-lasting radiative effect around the globe, reflecting incoming sunlight & lowering temperatures.

Early indications do not show extreme levels of SO2 in the stratosphere.

This means that the event appears unlikely to have a significant cooling effect on temperatures globally.

However, it's still early and more measurements are being taken + more eruptions are possible.

SO2 is a toxic, invisible pollutant.

In Tonga, possible short-term hazards to human health include acid rain & 'volcanic smog'.

While large & locally devastating for Tonga, the eruption looks unlikely to change the direction of the global temperature trend.