Peihui DAI，Lingling HUANG

College of Economics and Management，Huazhong Agricultural University，Wuhan 430070，China

Climate change has become a long-term constraint to sustainable economic and social development in various countries，and it is also a problem affecting the harmony between man and nature［2］.The effects of plans and strategies aimed at improving the human adaptability and community risk prevention capacity，will change to some extent due to differences in the perception of the public.Therefore，to develop more effective strategies to deal with climate change，it is necessary to understand the perception status of the communication objects［3］.In recent years，Liu Zongfa，Zou Jintai et al.study the impact of climatic change on the urban economic development，but few of them carry out studies from the risk perception of residents.Risk perception is the subjective judgment that people make about the characteristics and severity of a risk.It is the process of decision-makers to assess the risks contained in the situation［4］.The phrase is most commonly used in reference to natural hazards and threats to the environment or health，such as nuclear power.It lays great emphasis on the impact of the experience gained from intuitive judgment and subjective feelings on the individual cognition［5］.In this paper，we attempt to apply the concept of risk perception to the urban residents' subjective understanding of climatic change risks.Based on the environmental awareness，the perception of climatic change risks is defined as：urban residents' subjective feelings and understanding of predictable psychological hazards arising from urban climate change to their life and psychology，including the feelings and understanding of the possibility of harm and the degree of harm.Through survey and analysis，we study the urban residents' perceived risks and the differences in the choice of risk reduction measures，in order to enhance the urban residents' understanding of climate change in cities，and provide proposals for the urban residents to scientifically understand the climatic change risks and respond to climate change in cities.

1 Materials and methods

1.1 Study area and data sourcesWuhan（113°41′－115°05′E，29°58′－31°22′N）is the capital of Hubei province，People's Republic of China，and is the most populous city in Central China.It lies in the eastern Jianghan Plain at the intersection of the middle reaches of the Yangtze and Han rivers.Wuhan's climate is humid subtropical with abundant rainfall and four distinctive seasons.Wuhan is known for its oppressively humid summers，when dewpoints can often reach 26℃ or more.Spring and autumn are generally mild，while winter is cool with occasional snow.The monthly 24-hour average temperature ranges from 3.7℃in January to 28.7℃in July.Annual precipitation totals1269 millimeters，mainly from May to July；the annual mean temperature is16.63℃，the frost-free period lasts211 to 272 days.With monthly percent possible sunshine ranging from 31 percent in March to 59 percent in August，the city proper receives 1929 hours of bright sunshine annually.Extreme temperatures have ranged from－18.1 to 42.0℃.Since 2000，the average annual temperature has increased significantly；there hasbeen an increasing trend of precipitation；the humidity has dropped significantly；the dry island effects have appeared［6］.The urban residents feel deeply about the climatic change.The data used in this paper are from the research team's valid questionnaires on 295 urban residents in Wuhan City.Using the form of Likert scale，＂Environmental Protection Risk Perception Questionnaire＂is designed to measure the urban residents' risk perception of climatic change in the general social context and the reduction measures of climatic change risks.SPSS statistical software is used for data processing.In this study，the Cronbach coefficient is greater than 0.70，indicating that the scale reliability is good.This article learns from a lot of high-quality literature and survey scales，and the designed scale is reasonable.The questionnaire applicability is ensured through the group interviews，so the content validity is assured.The factor analysis results show that the factor extraction results are clear and the structure validity is good.

1.2 Research methods

1.2.1 Factor analysis.Factor analysis is a statistical method used to describe variability among observed，correlated variables in terms of a potentially lower number of unobserved variables called factors.For example，it is possible that variations in four observed variables mainly reflect the variations in two unobserved variables.Factor analysis searches for such joint variations in response to unobserved latent variables.The observed variables are modelled as linear combinations of the potential factors，plus＂error＂terms.It can minimize the information losses and integrate many of the original variables into a smaller number of composite indicators［7］.Factor analysis includes the following four steps：

（i）Seeing if there is a strong correlation between the original variables.It is a prerequisite for factor analysis.In this paper，we use KMO test and Bartlett sphericity test to verify the correlation between variables.If the KMO value is closer to 1，it means that there is a stronger correlation between variables，and it is more suitable for factor analysis.Kaiser believes that if the KMO value is greater than 0.7，the factor analysis can be performed；if the Bartlett value is greater，the corresponding P value will be lower than the given significance levelα，thus it can be held that the original variables are suitable for factor analysis.In this paper，α is set to0.01，and the SPSS running results show that the KMO value of the variable of residents' perception of climatic change risks is 0.854，the Bartlett value is 1911.291 and the significance level is 0；the KMO value of the variables of reduction measures of climatic change risks is0.754，the Bartlett value is1194.284 and the significance level is0.The results of KMO test and Bartlett sphericity test show that the variables are suitable for factor analysis.

（ii）Extracting the factors.The principal component analysis is used to extract factors，and since there is no order of magnitude difference in the variable values，there is no need to standardize the original data in this study.We first calculate the correlation matrix R，calculate the eigenvalues of R，and then select the latent roots with eigenvalues of greater than 1，to determine the number of factors and calculate the cumulative variance contribution rate.

（iii）Naming the factors.According to the factor loading matrix rotated using the varimax method，we analyze the actual meaning of the factors and name them.

（iv）Calculating the factor scores.

1.2.2 Cluster analysis.To explore the differences in different groups' perception of climatic change risks，this paper uses the＂factors＂from factor analysis of perceived risk of climatic change as the variables，and uses K-means clustering to carry out the cluster analysis of the respondents.The steps of K-means clustering are as follows：

（i）Specifying the number of clusters K.According to the relevant researches and system cluster analysis，this paper sets K to 5.

（ii）Using the way specified by the SPSS system to determine K initial points.

（iii）Classifying according to the principle of the shortest distance，calculating the Euclidean distance between each sample point and the initial point，and assigning the samples to the nearest category in accordance with the distance.

（iv）Redefining K cluster centers.Calculating the mean of variables in each category and regarding the mean center point as the new cluster center.

（v）Determining whether we can terminate the cluster analysis.According to the degree of deviation of the number of iterations from the cluster centers，the judgment is conducted.The number of iterations specified in this paper is 10，and the degree of deviation is 0.02.

2 Empirical analysis

2.1 Factor analysis of perceived risk of climatic change

We carry out the factor analysis of 23 variables.＂Influencing the tourism development＂and 3 other factors have high load in two or more factors，so the 4 variables are excluded in this paper according to the theory.The factors that＂climate warming making the sea level rise and flooding the coastal areas＂belongs to contain only this variable，and this variable is removed.Using principal component analysis，5 factors are ultimately extracted from the 18 variables，and the cumulative variance contribution rate of factor after rotation is66.096%.Table1 is the factor loading matrix obtained after the variance maximum value rotation.As can be seen from the table，the factors with high load are sequenced in descending order in terms of the coefficient，and regularly distributed in several key evaluation indicators.As can be seen from Table 1，the 5 variables correlated with factor1 from different levels reflect the adverse effects of climatic change on the environment，so it is called＂the environmental degradation risk＂；the 4 variables correlated with factor 2 are the possible effects of climatic change on industrial and agricultural production costs and yields，reflecting the impact of climatic change on human economic activity，so it is called＂the risk of damage to the economy＂；the3 vari-ables correlated with factor 3 reflect the impact of climatic change on human mental health，so it is called the risk of damage to the mental health＂；the3 variables correlated with factor4 are the adverse effects of climatic change on residents' physical health，so it is called＂the risk of damage to the physical health＂；the last 2 variables reflect the damaging effects of climatic change on international political harmony，so it is called＂the risk of damage to political harmony＂.

Table 1 Rotated factor loading matrix

In the above 5 factors extracted，the perception of the environmental degradation risk is the highest，and this risk is far away from the daily life of the residents，which shows that the frequent ecological damage events in recent years have prompted people to no longer rely solely on＂whether or not it is related to myself＂to evaluate the climatic change issues，and also shows that the recent media publicity has affected the public perception of climatic change issues.The economic losses and adverse effects on mental and physical health are still the important issues that the urban residents are concerned about，indicating that people have linked the climatic change with their own personal life，and they believe that the climatic change is gradually becoming an important factor affecting their quality of life.The perception of damage to political harmony is relatively low，which may be related to the fact that the impact of climatic change on the global political landscape is still at the potential level.The political harmony is far away from the urban residents' life，and the residents only sense this risk，but the feelings are not deep.

2.2 Cluster analysis of residents based on risk factorsAfter 10 iterations of cluster center changes，the result is zero，and the iteration is stopped.The factors are clustered into 5 groups，and the cluster mean square error of the5 variables is much larger than the mean square error within the cluster.The5 variables make the probability of no difference between clusters less than 0.001.

Table 2 The final cluster centers

After cluster analysis（as shown in Table 2），the first cluster contains84 samples，and the score of physical health and political harmony is high，so it is defined as the group＂those who are concerned about the body and politics＂；the second cluster contains 97 samples，and the score of the damage to the mental health is significantly higher than the score of other items，so it is defined as the group＂those who are concerned about the mental health＂；the third cluster contains 54 samples，and the score of the damage to the economy is high，so it is defined as the group＂those who are concerned about the economic development＂；the fourth cluster contains3 samples，and the score of each factor is low，so it is defined as the group＂those who ignore the climatic change risks＂；the fifth cluster contains57 samples，and the score of environmental degradation is significantly higher than the score of other items，so it is defined as the group＂those who are concerned about the ecological safety＂.

It is found from the analysis that the sample size of the group＂those who ignore the climatic change risks＂accounts for only 1.017%of the total sample size，indicating that currently urban residents have seldom ignored the risks arising from the climatic change.

2.3 Factor analysis of the residents' choice of risk reduction measuresSimilarly，we use the principal component analysis and the varimax orthogonal rotation method for factor analysis，and finally extract 5 factors.The cumulative variance explanation rate is66.29%，and the extracted common factors can explain the significance of the questionnaire indicators.The rotated factor loading matrix is shown in Table 3.

Table 3 Rotated factor loading matrix

As shown in Table 3，the urban residents' risk reduction measures of climatic change can be divided into five kinds：individuals and families to develop environmentally friendly habits；schools to strengthen publicity and education；businesses and governments to strengthen energy conservation and emission reduction；carrying out multi-agent environmental remediation；learning from the experience of the West.The variance explanation rate is 19.267%，16.046%，12.723%，10.322%and 7.849%，respectively.Thus，the currenturban residents believe that the individuals and families，schools，businesses and government are the subject addressing the climatic change；the variance explanation rate of individuals and families is the highest，indicating that the public eco-consciousness is awakening，people come to realize its strength in addressing the climatic change issues，and in their heart，schools，government and businesses are the important subject.The variance contribution rate of learning from the West is less than 8%，but it is still a factor that can not be ignored.The current urban resident shold rational attitude toward learning experience from the West.

2.4 The differences in the risk reduction measures between the cluster groupsWe carry out the variance analysis of the differences in the choice of climatic change risk reduction measures between the5 different risk groups，to understand the tendency of urban residents in addressing climatic change risks.

Table 4 Variance analysis

The variance analysis results are shown in Table 4.The significance level of individuals and families to develop good habits and businesses and governments to strengthen energy conservation and emission reduction for each cluster group is greater than the significance levelα＝0.1；in terms of the schools' publicity and education and learning the advanced experience of the West，the significance level is lower than 0.05，indicating that there are significant differences in the choice of the two measures between the cluster groups；for the multi-agent environmental remediation，the significance level of different cluster groups is less than 0.01，indicating that there are extremely significant differences in the choice of this measure between the groups.

3 Conclusions and recommendations

3.1 ConclusionsIn summary，the current residents' perceived climatic change risks are divided into 5 kinds：the environmental degradation risk，the risk of damage to the economy，the risk of damage to the mental health risk，the risk of damage to the physical health，and the risk of damage to the political harmony.According to these 5 risks，the urban residents can be clustered into 5 groups：those who are concerned about the body and politics，those who are concerned about the mental health，those who are concerned about the economic development，those who are concerned about the ecological safety，and those who ignore the climatic change risks.The residents' recognized risk reduction measures include individuals and families to develop good habits，businesses and government to strengthen energy conservation and emission reduction，schools to carry out publicity and education，carrying out multi-agent environmental remediation，and learning experience from the West.Meanwhile，there are significant differences in the choice of the risk reduction measures between different cluster groups.For the roles of individual and the family，business and government in the environmental protection，different groups have unanimous views，while for other measures，different groups have different understanding.

3.2 Recommendations

3.2.1 Continuing to encourage individuals and families to choose＂eco-consumption＂and＂green living＂.It is necessary to take measures to guide the residents' consumption and life，and help them to build environmentally friendly lifestyle，so as to gradually realize＂eco-consumption＂and＂green living＂，such as promoting green travel，implementing the ladder power price，advocating the use of waste and recycling of old material and subsidizing the families with good performance.

3.2.2 Augmenting the responsibility of businesses and government in environmental protection.Government should play an important role in directing.It should development the appropriate policies and measures to promote energy conservation and emission reduction in the whole society，improve and earnestly implement the relevant laws and regulations，learn the advanced management experience of the West，supervise the enterprises to positively take responsibility for environmental protection to reduce emissions of atmospheric pollutants，actively implement energy conservation plans，and consciously accept the supervision of the public and the media.

3.2.3 Strengthening the environmental protection publicity and education to improve public understanding of climatic change risks.Personal fear of risks is from the direct risk experience，or the information dissemination and interpretation of other social factors.Relevant organizations should strengthen national education and science popularization of climatic change，to guide people to form good habits and scientific literacy.Media organizations should play an important role in guiding.When there is a risk event，it should spread a lot of accurate，systematic and popular risk information to the public，and use the existing resources to help the public to overcome the uncertainties arising from the risks.

3.2.4 Clearly defining the responsibility of all parties for climate problems and exploring new government-led multi-agent model of participation.It is necessary to learn from the West，and explore the new government-led multi-agent model of participation.In the work，it is necessary to give full play to the initiative of all parties，enhance the publicity and education on carrying out environmental remediation measures，clearly define the responsibilities and obligations of all parties in protecting the environment and addressing the climatic change，and encourage the non－governmental organizations to strengthen environmental supervision，to fully reflects the will of the people in the relevant policy-making process.

［1］CAO LG，JIANG T.Prospect on evaluation report of the influence of change，adaptability and fragility of IPCC AR5 climate［J］.Advances in Climate Change，2011，7（2）：142.（in Chinese）.

［2］IPCCClimate Change2007：The physical science basis-working group Icontribution to IPCC fourth assessment report？London［R］：Cambridge University Press，2007.

［3］WANG XC，WANG SR.Climate change and its impacts on urban development strategies［J］.China Soft Science，2004（5）：107－109.（in Chinese）.

［4］LIU ZF，ZOU JT.The influence of climatic changeon urban social economy and the countermeasures—Taking the case of Wuhan City［J］.Science＆Technology Progress and Policy，2006，23（11）：89－92.（in Chinese）.

［5］Sitkin S，Pablo A.Reconceptualizing the determinants of risk behavior［J］.Academy of Management Review，1992（17）：9－38.

［6］QIN CJ.A study on the response ofWuhan climate under the background of global climate［J］.Wuhan：Huazhong Normal University，2009：27－29.（in Chinese）.

［7］XUEW.Data analysis based on SPSS［M］.Beijing：China Renmin University Press，2006：355－364.（in Chinese）.

［8］Oppenheimer M.Defining dangerous anthropogenic interference：The role of science［J］.The Limits of Science Risk Analysis，2005，25（6）：1399－1407.

［9］CHEN DY，HAO XF，TANG H.The path of Chinese corporate social responsibility under the changes of institutional environment［J］.China Polulation.Resources and Environment，2011，21（8）：51.（in Chinese）.

［10］ZHOU YF，LUOWE，XIAOWJ.Corporate social responsibility behavior and consumer responses——The moderator effects of consumer personal characteristic and price signal［J］.China Industrial Economy，2007，03：62.（in Chinese）.

［11］ZHANG L.Food security and health anxiety：An exploration of influential factors in hazard perceptions［J］.Journal of Shantou University（Natural Science Edition），2008，24（6）：67－71.（in Chinese）.

［12］LANQX，LI Y.The experiences of low-carbon economy development in European Union countries and the lessons to China［J］.China Business and Market，2012，26（8）：53－57.（in Chinese）.

［13］Lorraine Whitmarsh.Behavioural responses to climate change：Asymmetry of intentions and impacts［J］.Journal of Environmental Psychology，2009（29）：13－23.