Ecology and technosphere safety

Unit 3

Climate Change

1. Introduction. Look at the quotations.

a) NASA: “Arctic sea ice set a record low in September 2007.”

b) IPCC: “The global temperature will grow by 3 to 7 F.”  

c) EU commission: “Carbon dioxide emissions rose 3.5 % in 2009 across the European Union, as power demand and industrial output rose."

 

What do you know about the relationship between carbon dioxide emissions, average global temperature increase and melting of Arctic sea ice?

 

2. Vocabulary. Определите возможное значение следующих слов по их «родственникам» в русском языке. Значение некоторых из них может отличаться от оригинала в английском языке.

absorb, to have an effect, record, source, radiative, trend, to generate, approximately, to contain, chemical reactions

 

3. Reading. Find the answer to the question in Ex. 1 (Introduction) in the text below. What greenhouse gases are mentioned? Which one has the longest lifetime? Which one absorbs the most energy? What are the sources of greenhouse gases emissions?

Greenhouse gases

Greenhouse gases (GHGs) warm the Earth by absorbing energy and slowing the rate at which the energy escapes to space; they act like a blanket insulating the Earth. Different GHGs can have different effects on the Earth's warming. Two key ways in which these gases differ from each other are their ability to absorb energy (their "radiative efficiency"), and how long they stay in the atmosphere (also known as their "lifetime"). Earth's 2015 surface temperatures were the warmest since modern record keeping began in 1880, continuing a long-term warming trend. Most of the warming occurred in the past 35 years, with 15 of the 16 warmest years on record occurring since 2001. Last year was the first time the global average temperatures were more than 1 degree Celsius above the 1880-1899 average, a change largely driven by increased carbon dioxide and other human-made emissions into the atmosphere.

The Global Warming Potential (GWP) was developed to allow comparisons of the global warming impacts of different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO₂). The larger the GWP, the more a given gas warms the Earth compared to CO₂ over that time period. The time period usually used for GWPs is 100 years. GWPs provide a common unit of measure, which allows analysts to add up emissions estimates of different gases, and allows policymakers to compare emissions reduction opportunities across sectors and gases.

· CO₂, by definition, has a GWP of 1 regardless of the time period used, because it is the gas being used as the reference. CO₂ remains in the climate system for a very long time: CO₂ emissions cause increases in atmospheric concentrations of CO₂ that will last thousands of years.

· Methane (CH₄) is estimated to have a GWP of 28–36 over 100 years CH₄ emitted today lasts about a decade on average, which is much less time than CO₂. But CH₄ also absorbs much more energy than CO₂. The net effect of the shorter lifetime and higher energy absorption is reflected in the GWP. The CH₄ GWP also accounts for some indirect effects, such as the fact that CH₄ is a precursor to ozone, and ozone is itself a GHG.

· Nitrous Oxide (N₂O) has a GWP 265–298 times that of CO₂ for a 100-year timescale. N₂O emitted today remains in the atmosphere for more than 100 years, on average.

· Chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆) are sometimes called high-GWP gases because, for a given amount of mass, they trap substantially more heat than CO₂. The GWPs for these gases can be in the thousands or tens of thousands. The environmental concern for CFCs follows from their long atmospheric lifetime (55 years for CFC-11 and 140 years for CFC-12, CCl₂F₂), which limits our ability to reduce their abundance in the atmosphere.

The primary sources of greenhouse gas emissions are transportation, electricity production, industry, commercial and residential sources.

Transportation. The transportation sector generates the largest share of greenhouse gas emissions. Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90 percent of the fuel used for transportation is petroleum based, which includes primarily gasoline and diesel.

Electricity production generates the second largest share of greenhouse gas emissions. Approximately 62.9 percent of our electricity comes from burning fossil fuels, mostly coal and natural gas.

Industry. Greenhouse gas emissions from industry primarily come from burning fossil fuels for energy, as well as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials.

Commercial and Residential. Greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that contain greenhouse gases, and the handling of waste.

 

4. Word formation. Complete the chart. Mark the word stress. Highlight the word suffixes in the third column. Pay attention to the word stress.

 

Part of speech:	Part of speech:	Part of speech:
		different
absorb
reflect
insulate
	efficiency
	occurrence
increase
	emissions
	comparison
	impact
	estimate

5. Vocabulary. Fill in the gaps in the sentences with the most appropriate word, (a), (b), (c) or (d).

 

1. Earth's surface …………… radiation from the sun.

(a) emits (b) reflects (c) responds  (d) enhances

2. Greenhouse gases …………… infra-red radiation in the atmosphere.

(a) increase (b) reflect (c) absorb (d) stop

3. The concentrations of greenhouse gases ………… due to the burning of fossil fuels.

(a) enhance (b) fall (c) increase (d) decrease

4. The ………… global temperature is expected to rise by 1.4 to 5.8 degrees C by the year 2100.

(a) medium (b) middle (c) average (d) estimated

5. A temperature increase of 0.6 degrees C ………… last century.

(a) enhanced (b) existed (c) rose (d) occurred 

 

6. Grammar. Look at the sentences. What verb tenses are used? Why?

 

Snow cover has decreased by some 10 per cent in the mid- and high latitudes of the Northern Hemisphere since the late 1960s.

The annual duration of lake and river ice cover apparently shortened by about two weeks during the 20th century.

 

The text describes changes in extreme weather events. Fill in the gaps using the correct verb forms.

 

Since 1950, the number of heat waves _____ (increase). The extent of regions affected by droughts _____ also _____ (increase) as precipitation over land _____ (decrease) while evaporation _____ (increase) due to warmer conditions. Generally, number of heavy daily precipitation events _____ (rise), but not everywhere. Tropical storm and hurricane frequencies vary considerably from year to year, but evidence suggests substantial increases in intensity and duration since the 1970s.

 

7. Grammar. Passive and active forms. Look at the examples to learn how the Passive Voice is formed.

The net effect of the shorter lifetime and higher energy absorption is reflected in the Global Warming Potential (GWP).

The GWP was developed to allow comparisons of the global warming impacts of different gases.

 

Fill in the gaps in the text using the correct forms of the verbs in brackets.

 

Forests _______ (call) “carbon sinks” because they ______ (take) CO2 from the air and _______ (store) it. When trees _______ (cut down) and _______ (burn), the CO2 that _______ (store) in them ______ (release) back into the air. Scientists ______ (believe) that every year, 2 billion to 5 billion tonnes of CO2 ______(release) into the air from forests that ______ (cut down) and ______ (burn).

 

8. Grammar. Express the same ideas using passive forms. Use the Passive with “by” where appropriate.

a) Scientists first measured atmospheric concentration of CO2 at the South Pole in 1958. 

b) Climatologists use large computer models to estimate future possible warming.

c) The governments signed the Montreal Protocol in 1989.

d) Under the Protocol the industrialized countries stopped CFCs production.

e) Until the 1970-s people thought that CFCs were absolutely safe.

f) NASA uses satellites to check the ice in the Arctic region.

g) Ultraviolet radiation (UV-B) causes mutations in animal and plant cells.

e) They founded IPCC in 1972.

9. Reading. Read the article. Prepare to talk on the following questions.

1. What are two reasons why sea level has risen?

2. Does sea level rise have only social and economic consequences?

3. What does amplified Arctic warming mean?

4. What threats can lead to population reduction or even extinction of Arctic animals?

5. Explain why warmer temperatures lead to changes in precipitation patterns.