American Public Perception of Global Warming and Their Support of Particular
Carbon-Trade Policy
Xiuxiu Zhao
The Question with which the research is concerned
The global attitude survey, conducted May 18 to June 16, 2009 by Pew, revealed
that majorities in 23 of 25 countries agree that protecting the environment should be
given priority, even at the cost of slower economic growth and job losses. However,
concern about climate change is much less pervasive in the United States. As the world
second largest emitter of greenhouse gas and the aspiration to be the world leader on this
issue, it is very important to analyze the divisions (Sex/ Education/Age/ Party identity) of
American publics opinion towards the issue of global warming, thus analyze whether the
awareness of this issue can, to some extent, transfer into support of related domestic
policy.
The Theoretical Framework
Global warming is on the one hand, one of most concerned global environmental
issue that faces the human being; on the other hand, not the most urgent domestic issue
facing America, especially during the economic recession. So there are must be a division
of perception of this issue across different social groups (demographically). I think
people who are more liberal (indicates different party identity), young adults and better
educated are more concerned of the environmental issue. Female are generally more
sensitive about environmental issue. The more people are aware of the issue of global
warm, the more they think this issue as serious. Furthermore, people who are more
informative and concerned about the global warming, should be more supportive of the
domestic policy of ‘carbon trade’ to deal with the situation.
Operational Definition of the Concept
Survey data from PEW RESEARCH CENTER FOR THE PEOPLE & THE
PRESS October 2009 Political Survey will be used to examine the research question.
American public awareness of the fact of global warming- Variable asking the
respondent whether or not there is solid evidence that the average temperature on earth
has been getting warmer over the past few decades;
American public perception of climate change as a human creature- Variable asking
respondent if they believe that global warming is a human creature;
American public awareness of the seriousness of the climate change issue- Variable
asking respondent the emergency degree of global warming issue
American concerns on the issue of global warming-distinguished on the data set based
on two variables: 1) Variable asking the respondent whether or not there is solid evidence
that the average temperature on earth has been getting warmer over the past few decades;
2) Variable asking respondent the emergency degree of global warming issue
(The variable asking respondent if they believe that global warming is a human creature
is moved out after reliability analysis)
American public awareness of the general government policy towards climate changeVariable asking respondent whether they heard of Carbon trade policy or not
American public support of policy priority given to the issue of climate changeVariable asking respondent if they are in favor of carbon trade policy.
Better educated-distinguished on the data set based on the variable: education (college
graduate, postgraduate)
Young adult-distinguished on the data set based on the variable: age (18-30)
Specifically, the variables in the dataset are
Q41. From what you've read and heard, is there solid evidence that the average
temperature on earth has been getting warmer over the past few decades, or not?
Q.42 Do you believe that the earth is getting warmer mostly because of human activity,
such as burning fossil fuels, or mostly because of natural patterns in the earth's
environment?
Q.43 In your view, is global warming a very serious problem, somewhat serious, not too
serious, or not a problem?
Q.55 How much, if anything, have you heard about a policy being considered by the
president and Congress called "cap and trade" that would set limits on carbon dioxide
emissions? Have you heard a lot, a little, or nothing at all?
Q.56 Do you favor or oppose setting limits on carbon dioxide emissions and making
companies pay for their emissions, even if it may mean higher energy prices?
The independent variables are Sex, education, party identity, and age
I recode age and education to better fit into the hypothesis.
For age, 18 thru 30=young adults (14%), 31 thru 45=middle age (20%), 46 thru
65=over the hill (41%), and 66 thru hi=retired (25%)
For education, under ‘associate degree of college, non-4 years degree’ is not well
educated (62%), and for college and postgraduate graduates are well educated (40%).
Hypothesis and SPSS Operation to testify the hypothesis
H1: Democrats are more concerned about the seriousness of global warming than
republicans and independences.
I use one-way ANOVA to testify this hypothesis.
The mean square between groups is much larger than the mean square within
groups, and the F test is statistically significant at the p<=.05 level (.000).
So the samples are statistically significant enough to represent different population. There
are significant differences between the means of the groups taken as a whole.
Since the Levene statistic is statistically significant at the .000 level, which is smaller
than .05, we cannot assume equal variances for each groups of the samples. So
homogeneity is not assumed.
Since the homogeneity is not assumed, we select Tamhane’s T2 as the post hoc
test for the differences between pairs of the means. And as I mentioned before, there are
unequal sizes for each groups. Tamhane’s T2 is a more conservation estimate.
Democrats are the ones who are most likely to think global warming as a serious
problem. Republican are much less likely to think so, they have a mean difference of 1.1;
and independent are in between, all of these are statistically significant to represent the
whole population.
H2:Young Adults are more concerned about the seriousness of global warming.
I perform the same operation (one way ANOVA) as last one to test this
hypothesis, which shows that young adult are more concerned about the seriousness of
the global warming than people who are over the hill and retired, they are statistically
significant at p<=.05 level; since the mean difference between young adults and middle
age is not statistically significant (0.335), we can not testify the hypothesis whether
young adult are more concerned of global warming than middle age as well.
H3:Female are more concerned than male about the seriousness of global warming.
I use independent samples T-test to testify the hypothesis.
The mean of male group’s concern of the seriousness of the global warming is 2.39;
while the mean of female group is 2.05. The mean difference between two groups is
0.34. The equal variance is not assumed, and the mean difference is statistically
significant at 0.00 level, which indicates although the mean difference between the
concerns of female and male is slightly small, we can support the hypothesis that female
are slightly more concerned than male about the seriousness of global warming, and the
result we observed is not occurred by chance.
H4: People of higher education are more concerned about the seriousness of global
warming.
I use independent samples T-test to testify the hypothesis.
The mean difference between two groups of different level of education is 0.02; the equal
variance is assumed, and the mean difference is not statistically significant at 0.00 level
(0.756).
Surprisingly, We cannot reject the null hypothesis and we cannot support the
research hypothesis that people of higher education are more concerned about the
seriousness of global warming. There is no difference between the means, and the
relationship in not statistically significant. The reason for this result needs further
investigation.
Since Partisan differences also are evident on evaluations of the seriousness of
global warming, I want to go further to see whether there is a correlation between party
identities and the perception of global warming as human creature.
H5: Democrats are more likely to believe that global warming is a human creature
than republican and independence.
I use crosstab to testify the hypothesis. The result is shown as the following table.
The contingency table analysis of perception of global warming as a result of human
activity and party identification supports my hypothesis that ‘Democrats (76%) are more
likely than Republican (53%) or independence (70%) to believe that global warming is
resulted from human activities ’; and the relationship is statistically significant at P < 0.1
level.
GW because of
Republican
Democrat
Independence
53
76
70
47
24
30
human activity
GW as a natural
pattern
The measure I used for association is Cramer’V. With a Cramer’V coefficient of 0.174,
which is somewhat weak support for the correlations.
H6: Democratic are more likely to be in favor of carbon-trade policy than republican
and independence.
I use crosstab to testify the hypothesis. The result is shown as the following table.
The contingency table analysis of carbon trade policy supporting and party identification
supports my hypothesis that ‘Democrats (72%) are more likely than Republican (38%) or
independence (58%) to support the carbon-trade policy’, and the relationship is
statistically significant at 0.000 level.
Republican
Democrat
Independence
Favor
38
72
58
Oppose
62
28
42
The measure I used for association is Cramer’V. With a Cramer’V coefficient of 0.269,
there is moderate support for the correlation between party identity and supporting of
carbon-trade policy.
There probably be a positive relationship between people’s awareness of this issue and
their concerns about the seriousness of the global warming situation.
H7: Views about the seriousness of global warming is positively related to whether
people think there is solid evidence the earth is warming.
I use Pearson’s R to testify the hypothesis, it turned out the Pearson’s R coefficient for the
relationship of the two variables is 0.564, which shows that there is 56.4% of
improvement of chances we can make prediction on a subject’s score concerns of the
seriousness of global warming issue if we know whether they think there is solid evidence
the earth is warming, and vice versa; the relationship we observed is statistically
significant at 0.000 level.
H8: Views about the seriousness of global warming are related to whether people think
global warming is caused by human activities.
I use Pearson’s R to testify the hypothesis, it turned out the Pearson’s R coefficient for the
relationship of the two variables is 0.459, which shows that there is 45.9% of
improvement of chances we can make prediction on a subject’s score concerns of the
seriousness of global warming issue if we know whether they think the global warming is
caused by human activities, and vice versa; the relationship we observed is statistically
significant at 0.000 level.
H9: There is correlation between people’s concerns of the issue of climate change and
their supportiveness of the carbon trade policy.
First. I use three variables as index to construct the concept of people’s concern of issue
of climate change. The three variables are Q41. From what you've read and heard, is there
solid evidence that the average temperature on earth has been getting warmer over the
past few decades, or not? Q.42 Do you believe that the earth is getting warmer mostly
because of human activity, such as burning fossil fuels, or mostly because of natural
patterns in the earth's environment? Q.43 In your view, is global warming a very serious
problem, somewhat serious, not too serious, or not a problem?
After run frequency of three variables, I find out that Q42 has half of missing values,
which is almost half size of the size of the other two, and the reliability coefficient of
these three variables is lower than the Crobach’s alpha of the two variables is (q41+q43),
which is acceptable as 0.608, so I syntax the new variable concern on global warming as
Compute concern=q41+q43. Variable labels concern ‘public concern on global
warming’.
Then I use Pearson’s R to testify my hypothesis, and it shows Pearson’s R coefficient for
the relationship of the concerns on global warming and supportiveness of carbon-trade
policy is 0.510, which shows that there is 51% of improvement of chances we can make
prediction on a subject’s score favor of the carbon-trade policy if we know whether they
are concerned of the issue of global warming, and vice versa; the relationship we observed
is statistically significant at 0.000 level.
H10: There is correlation between people’s awareness of the carbon-trade policy and
their supportiveness of the carbon trade policy.
I use Pearson’s R to testify my hypothesis, and it shows Pearson’s R coefficient for the
relationship of the awareness of the carbon-trade policy and supportiveness of this policy
is -0.202, the relationship we observed is not statistically significant at p<=0.05 level,
which shows that we can not make any prediction of people’s score on supportiveness of
the carbon-trade policy if we know the degree of their awareness of this policy, and vice
versa.
Analysis
Frequency for General Description
Generally, the survey finds that 56% think there is solid evidence that the average
temperature on earth has been getting warmer over the past few decades. Almost half of
values (44%) for the Q42 are missed, for the valid values, 62% of respondents (35% in
total) believe that the earth is getting warmer because of human activities. A majority
(65%) of the public continues to view global warming as a very (34%) or somewhat
(29%) serious problem. About a third (32%) says global warming is not too serious (15%)
or not a problem at all (20%).
Despite the growing public skepticism about global warming, the survey finds
more support than opposition for a policy to set limits on carbon emissions. Half of
Americans (50%) favor setting limits on carbon emissions and making companies pay for
their emissions, even if this may lead to higher energy prices; 38% oppose imposing
limits on carbon emissions under these circumstances.
This issue has not registered widely with the public. Just 19% say they have heard
a lot about the so-called “cap and trade” policy that would set carbon dioxide emissions
limits; another 33% say they have heard a little about the policy, while a majority (47%)
has heard nothing at all.
Specifically, one important point we find out is that the issue of climate change in United
States has a highly partisan nature. Young adult are now far more likely than older
Americans to view global warming as a very serious problem, although not necessarily
more concerned of this issue than middle age.
As expected, views about the seriousness of global warming are also related to whether
people think there is solid evidence the earth is warming and whether it is human caused.
For the carbon-trade policy, opinion about cap and trade is positively related to views
about global warming. However, people’s awareness of the carbon-trade policy not
necessarily transfer to their support of this policy.