Climate and Climate Change Quiz 4

What is an aerosol

A tiny solid particle or liquid droplet suspended in air. Aerosols enter the atmosphere through either natural or anthropogenic (human) sources

What are some anthropogenic sources of aerosols

Aircraft, furnaces, factories, vehicles, and power plants. Most anthropogenic aerosols are from burning fossil fuels.

What are the direct and indirect effects of aerosols on climate

Direct effect: the scattering, reflection, and absorption of incoming solar radiation by aerosols

Indirect effect: aerosols serving as cloud condensation nuclei (CCN), encouraging the formation of cloud droplets

What are the contrasting effects of sulfate aerosols versus black carbon on temperature

Sulfate aerosols are reflective of solar radiation, causing cooling. In contrast, black carbon absorbs solar radiation, causing warming.

What is radiative forcing

The net change in the energy balance of the Earth system due to an imposed peturbation (ex: adding greenhouse gases or aerosols to the atmosphere)

Radiative forcing is measured in Watts per meter squared (w/m2)

When did Mount Pinatubo erupt and what gas did it release into the stratosphere

Erupted in June 1991, the eruption injected about 20 megatons of sulfur dioxide into the stratosphere

The eruption contributed to the cool summer in the following year, 1992, across the Northern Hemisphere

On average, how does a major volcanic eruption affect air temperatures

On average, a major volcanic eruption leads to hemispheric cooling of 0.2-0/;5 degrees C for 1-3 years

What was the climactic impact of the eruption of Mount Tambora in 1815?

Led to the "year without a summer" in 1816 across Europe and northeastern North America

What are the largest rainforests in the world

1st- Amazon in South America

2nd- Congo in Africa

What is biodiversity

The measure of the degree of variety of life in a given region. The Amazon Rainforest hosts about 25% of the Earth's terrestrial species, indicating high biodiversity.

What is LAI

Leaf area index, representing the proportion of Earth's surface covered by leaves. The highest global LAI values are often found in tropical rainforests.

What is the early anthropogenic hypothesis

According to the early anthropogenic hypothesis, proposed by Bill Ruddiman, agricultural practices even thousands of years ago impacted global atmospheric concentrations of greenhouse gases and the global climate.

Why are cities generally warmer than rural areas

Cities have fewer trees for shading, a lower surface albedo due to asphalt, and less available surface moisture.

How do white roofs affect air conditioning demand

The use of reflective) high albedo) white roofs generally reduces the energy demand for air conditioning

What are some types of climate proxies

Tree rings, fossil pollen, and ocean and lake sediment cores. The two most commonly used climate proxies are biotic proxies and geological-geochemical proxies.

What is paleoclimatology

The scientific field that involves reconstructing past climates in order to lengthen the climate record for statistical analysis and risk assessment, encompass a broader range of fluctuations in Earth's climate, and examine past events as they could happen again in the future

What is dendroclimatology

The reconstruction of past climate periods based on analysis of tree rings

This analysis usually focuses on subpolar trees in the mid-high latitudes. Tropical trees are less useful because they typically do not have well-defined seasonal growth rings

What is calibration in terms of climate reconstructions?

Climate reconstruction requires calibration, or a comparison of measurements, of modern climate forcings with modern environmental responses

Which paleoclimate proxies generally have the longest climate records?

Continental, coastal sediments and ocean sediments have the longest climate records, going back furthest in time, compared to shorter records from instrumental data, historical data, tree rings, ice cores, lake sediments, and coral reefs.

What is an ice core

A cylinder of ice drilled from an ice sheet or glacier

What is the study of pollen and organic micro-fossils

Palynology

What is a megadrought

A drought lasting at least 2 decades

Tree ring data suggests that some past North American droughts were more severe than the 1930s Dust Bowl and persisted for several decades

What was the Last Glacial Maximum

The last major glacial climactic episode and took place about 20,000 years ago. The LGM was 4-5 degrees C cooler than present day.

CLIMAP and COHMAP were 2 major international efforts to deepen our understanding of the LGM and subsequent global climates.

3 recent climate events during the past 2 millennia

The three key climate events of the last 2,000 years include the Medieval Climate Anomaly (also called the Medieval Warm Period), the Little Ice Age, and the Anthropocene

What were some impacts of the Little Ice Age

Caused an expansion of alpine glaciers, irregular harvests contributing to the collapse of the Ming Dynasty, and the loss of the vineyards in England

What climate record is Michael Mann famous for

The hockey stick model of historical Northern Hemispheric air temperatures during the past 1,000 years

What is Arctic amplification

The greater warming trend over the Arctic compared to most of the world, due to snow and ice albedo feedbacks

Has land or ocean been warming more rapidluy

Land is warming faster than oceans due to differences in heat capacity

How have temperatures changed in the troposphere and stratosphere during recent decades

The troposphere is getting warmer due to greater levels of greenhouse gases, and the stratosphere is getting colder due to greater levels of greenhouse gases and reduced stratospheric ozone

What temperature threshold is applied when computing heating and cooling degree days

Degree days are the difference between the daily mean temperature and 65 degreed F

How has extreme precipitation changed in the Midwest and Northeast United States

During recent decades, the Midwest and Northwest US have experienced the largest increases in extreme precipitation events in the country

How has Wisconsin's climate changes in recent decades

Temperatures have increased especially in winter-spring and nights have warmed more than days; the growing season has expanded; spring phenological events (ex: blooming of plants, arrival of birds) are occurring earlier; there have been minimal changes in extreme hot days, but extreme cold events have been much less common.

What is the cryosphere

The frozen component of the climate system, containing glaciers, snow, ice, and permafrost

What has happened to Muir Glacier in Alaska since 1941

Mountain glaciers are sensitive to climate change. Since 1941, Muir Glacier has dramatically retreated due to warming. Most glaciers in the world are retreating to higher elevations

What have the GRACE satellites told us about changes in the Greenland Ice sheet?

According the the GRACE satellites, the ice sheet that has lost the most mass is the Greenland Ice Sheet

Which lake in the Madison area has responded to the warming trend with a trend of 34 less days frozen since 1853?

Since 1853, the amount of time that Lake Mendota remains frozen each winter has diminished by 34 days due to rising temperatures

Which would a potential elimination of summer ice cover in the Arctic impact the Northwest Passage

If the Arctic becomes seasonally ice free, ships can take a shortcut through the Northwest Passage and more quickly travel between the North Atlantic and North Pacific

Which reservoir is the largest storage of global water in the hydrosphere?

The largest reservoir of global water in the hydrosphere is the oceans, seas, and bays, adding up to 97% of global water

Which is the parasite and associated waterborne disease that becomes more abundant when precipitation events and resulting runoff to lakes are enhanced and lakes are warmer

Cryptosporidium is this parasite and associated waterborne disease

Milwaukee experience the greatest outbreak of cryptosporidium in our country in 1993

What causes ocean acidification

It results from emissions of carbon dioxide (released by vehicles, power plants, and other human sources) combining with seawater to form carbonic acid

The excess amount of anthropogenic carbon dioxide absorbed by the ocean leads to ocean acidification, lowering its PH

What percentage of Earth's ice is contained in the Antarctic ice sheet

90% of all ice on the planet

What was the Younger Dryas

A relatively cool time period around 11,000-10,000 years ago, in which remnant ice sheets over North America and Europe partly advanced

How has Earth's temperature changed since the mid-1800s

Rose about 2 degrees F over the last 150 years

What are some surfaces in the Earth's climate system with high albedo

Albedo is the fraction or percentage of radiation striking a surface that is reflected by that surface

Snow, ice, and clouds have high surface albedo, meaning they are very reflective to shortwave radiation from the Sun