IPCC Report (Quiz 7) Flashcards

What are floods?

river capacity is overun, and water can not be restricted to the channel (unconfined flow)

How will pluvial/flash floods be impacted by climate change?

• More rain per event (6-7% per degree Celsius of warming), wet extremes do get wetter

• Flash floods are expected to get more extreme almost everywhere

  • Reason: Flash floods occur when rainwater overwhelms the local drainage or soil capacity.

  • The southwestern US is very prone to flash flooding

    • Dangerous: It happens very quickly with big walls of water traveling at high speeds

How will river floods be impacted by climate change?

• River floods happen during after spring, snowmelt and are multi-day phenomenon. They can be compounded by rainfall events and are more complicated than flash flooding

  • • In places with longer dry spells, river flows are lower per storm. Rivers have more room to handle rain events when they happen (stream capacity)

      • Places that are experiencing dryer conditions will not have this increase in river flooding

  • Overall: River floods are getting more extreme despite regional differences

    • River flows will be flowing less water than currently where warming temperatures are. Less extreme in dry places.

    • Most of the world: low flows

What will happen to coastal flooding and storm surges due to climate change?

• Storm Surge (a form of coastal flooding): seawater moving onto land during a coastal storm

  • Universally (EVERYWHERE) getting more intense (inundation areas increase in places with sea level rise)

    • Ex: Hurricane Sandy, Hurricane Ian

    • High-impact factor as many people live near the coast

  • If you start from a higher background sea level, the same storm produces a more severe coastal flood!!

Will the number/amount of storm events increase due to climate change?

• NO there will not be an increase in the number of storms

  • Why? Because there are going to be fewer precipitation events

    • Warmer air holds more water vapor so it takes longer to “recharge” the atmosphere to saturation between each storm, so you get more infrequent storms

What will and will not happen to local thunderstorms/convectional storms because of climate change?

• WILL NOT: be a larger number of thunderstorms

  • WILL:

    • storms will rain/snow heavier per event because there is more water vapor in the air

    • Heavier precipitation means each storm releases more total latent heat because of climate change-induced temperature modulation of water vapor. This makes stronger winds from this “extra” energy.

      
      

What will happen to mid-latitude cyclones with fronts (extratropical cyclones)?

• There will NOT be more of these

  • These storms are powered by north-south temperature differences, and so since the Arctic and tropics are both warming, this temperature difference is increasing, but not being magnified (actually weakening)

• The weakening of the temperature difference and increase in latent heating cancel each other out, so there is little wind change.

What will happen to tropical cyclones (hurricanes/typhoons) due to climate change?

These storms are also powered by vertical temperature differences between the surface of the ocean and the upper troposphere.

• You’ll get hurricanes with low pressure (lifting) outside that is releasing latent heat, and a high-pressure eye

• There will be slightly stronger hurricanes due to a modest but clear wind increase, despite little change in the vertical temperature contrast.

  • (6% more latent heat per degree of warming) (3% stronger winds per degree C)

  • Will increase the number of storms that will reach Category 3-5

Why will there not be an increased number of tropical cyclones (hurricanes/typhoons) in response to climate change?

• Convection will not get stronger since the upper-cold troposphere and warm tropical ocean are both warming; so there will not be much of a change

What will happen to the location of tropical cyclones (hurricanes/typhoons) due to climate change?

• There will be a shifting of location towards Northern Europe and Alaska (as temperatures continue to warm in the northern hemisphere) but overall, the storms will NOT become more numerous

In what capacity will storms get stronger?

• There will be a strengthening in terms of more precipitation per storm

• stronger in the sense of more coastal flooding (especially in places with background sea level rise)

• No real temperature differences globally (except in Antarctica), so…

  • winds in mid-latitude are weakening, not strengthening

What will happen to drought symptoms as a result of climate change?

• COMPLICATED (often the drought definition has some reference to agriculture and how dry spells affect food production)

  • Longer dry spells and more frequent low flows in most of the world

    • Warmer conditions for longer periods

• It will get more severe in some places and less severe in other places

  • The Southwestern US has been experiencing a “megadrought” for multiple decades

What is the Coastal Vulnerability Index (CVI)?

This is the numerical ranking system used to assess how vulnerable different coastal areas are to sea-level rise from being inundated with water and erosion.

This ranking is determined by averaging the scores of five different factors: geomorphology, regional coastal slope, tide range, wave height, and relative sea-level rise.

What is geomorphology and how does it contribute to the coastal vulnerability of a location?

Geomorphology is the shape, material, and slope of the coast accounted.