Volcanic explosivity index

• Today, the Honourable Bill Blair, President of the King's Privy Council for Canada and Minister of Emergency Preparedness, released the National Risk Profile , Canada's first public, strategic, national-level disaster risk assessment.
• It provides a national picture of disaster risks facing Canada, and the existing measures and resources in our emergency management systems to address them.
• The report will increase resiliency in a few different ways:
  It provides decision-makers with a consolidated, national picture of disaster risk and associated capabilities, to understand how and where to intervene to build resilience.
• The next phase of the National Risk Profile will focus on heat events, hurricanes and space weather.

• By some estimates, a billion native animals died up and down Australia’s east coast.
• While Sydney’s skies are blue again, Australia’s Black Summer has kept scientists around the globe busy.
• Now, new research by American scientists suggests the Black Summer fires were massive enough to influence the El Niño Southern Oscillation cycle.
• They could have been made more likely by the Black Summer fires.

Where there’s fire, there’s smoke

• We also know volcanoes can influence the tropical Pacific, and thus affect whether an El Niño or a La Niña phase develops.
• Volcanic ash gets blown high into the stratosphere, the part of the atmosphere just above the clouds where long-haul airplanes fly.
• Then, sunlight gets reflected before it reaches the ground, thus cooling the surface much like an umbrella can.

Is bushfire smoke the same as volcanic ash?

• It’s tempting to equate smoke with ash, and assume a large enough bushfire would have similar effects to a volcano.
• That might sound unimportant, but the rotten egg smell – which comes from sulfur – indicates major differences in the composition of volcanic ash and bushfire smoke.
• Bushfire smoke is hot, though, and hot smoke rises well.
• They found bushfire smoke does indeed shade the surface from sunlight in these simulations.

Clouds matter

• Under specific conditions, some smoke particles can interact with droplets in clouds and make clouds thicker and brighter.
• The researchers were able to show the brightness of the clouds over this area increased considerably just around the time when the smoke particles arrived.
• These brighter, whiter clouds reflected more sunlight back into space and shaded the surface underneath.
• Follow the chain: huge volumes of smoke blow east where they whiten clouds, cool the seawater, and cause less water to evaporate.

Is the link now proven? Not quite

• For one, the ENSO cycle in the simulation was heading for a double La Niña even without the impact of the smoke.
• To prove or disprove the link, we’ll have to simulate the impact of ballooning Black Summer smoke plumes across many different models.
• Read more:
  Smoke from the Black Summer fires created an algal bloom bigger than Australia in the Southern Ocean

• Cold spells often bring climate change deniers out in force on social media, with hashtags like #ClimateHoax and #ClimateScam.
• Yet many people believe these claims, and the political result has been reduced willingness to take action to mitigate climate change.

The allure of black-and-white thinking

• That mistake is the cognitive error known as black-and-white thinking, also called dichotomous and all-or-none thinking.
• As I explain in my book “Finding Goldilocks,” black-and-white thinking is a source of dysfunction in mental health, relationships – and politics.
• People are often susceptible to it because in many areas of life, dichotomous thinking does something helpful: It simplifies the world.
• In dichotomous thinking like this, a single exception can tip a person’s view to one side.

The all-or-nothing problem

• Climate change deniers simplify the spectrum of possible scientific consensus into two categories: 100% agreement or no consensus at all.
• Members of Congress have used that disinformation to block or weaken federal policies that could slow climate change.

Expecting a straight line in a variable world

• However, complex variables never change in a uniform way; they wiggle up and down in the short term even when exhibiting long-term trends.
• Most business data, such as revenues, profits and stock prices, do this too, with short-term fluctuations contained in long-term trends.

Failing to examine the gray area

• Climate change deniers also mistakenly cite correlations below 100% as evidence against human-caused global warming.
• They miss the gray area in between: Greenhouse gases are indeed just one factor warming the planet, but they’re the most important one and the factor humans can influence.

‘The climate has always been changing’ – but not like this

• As increases in global temperatures have become obvious, some climate change skeptics have switched from denying them to reframing them.
• Their oft-repeated line, “The climate has always been changing,” typically delivered with an air of patient wisdom, is based on a striking lack of knowledge about the evidence from climate research.

• What causes volcanoes to erupt?
• – Avery, age 8, Los Angeles
  What causes volcanoes to erupt?
• I want to learn more about what causes volcanoes to erupt.
• The proximity of people and buildings makes it important to study volcanoes and understand the hazards.

How volcanoes blow their stacks

• Over time, magma – which is melted rock mixed with gas and mineral crystals – accumulates in an underground chamber beneath the volcano.
• The magma at Mauna Loa forms when a hot mantle plume – think of a conveyor of heat – partly melts rock in the mantle.
• The volcano is essentially an opening that lets magma out onto the surface of the Earth.

Types of volcanoes

• Its sides slope gently downward in all directions.
• Semeru’s most recent eruption started when heavy rains washed away rocks near the top of the volcano.

The dangers

• The force of lahars can move huge boulders and destroy bridges and buildings.
• Mount Semeru’s recent eruption covered nearby villages with ash – tiny particles of rock that can go deep into lungs, causing irritation and making it hard to breathe.
• As falling ash accumulates, it can smother crops, contaminate water supplies and trigger the collapse of buildings.
• We won’t be able to answer every question, but we will do our best.