A Clear and Present Danger
to the Caribbean:
Climate Change or Climate Alarmism?
Reynold J. Stone
Department of Food Production
Warming Trend
Percent of Days Tmax > 90th Percentile
30
Y = -254 + 0.132X
25
Warm Days (%)
20
P = 0.004
95%CI = {0.044, 0.220}
R2 = 0.186
15
10
5
0
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
Percent of Days Tmax > 90th Percentile
30
25
Warm Days (%)
20
15
10
5
0
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
Wilks, D.S. 1995. Statistical Methods in the Atmospheric
Sciences. Academic Press, San Diego.

It is not sufficient to blindly feed data to a computer
regression package and uncritically accept the results.
Some of the results can be misleading if the
assumptions underlying the computations are not
satisfied. Since the assumptions pertain to residuals, it
is important to examine the residuals for consistency
with the assumptions made about their behaviour.
Assumptions of OLS Regression

Linearity
 Homoscedasticity
 Independence
 Normality
 Outliers
Anscombe, F.J. 1973. Graphs in Statistical
Analysis. American Statistician 27: 17-21.
Residual Patterns
Residual Plot
5
4
Standardized Residuals
3
2
1
0
-1
-2
-3
4
5
6
7
Fitted Y Values
8
9
10
Normal Plot
3
2
Nscore
1
0
-1
-2
-3
-2
-1
0
1
2
Standardized Residuals
3
4
5
Percent Warm Days (1958 -1978)
30
Y = 124 - 0.060X
25
P = 0.304
95%CI = {-0.179, 0.059}
Warm Days (%)
20
R2 = 0.056
15
10
5
0
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
Percent Warm Days (1979 -1999)
30
Y = -600 + 0.306X
25
P = 0.069
95%CI = {-0.026, 0.638}
Warm Days (%)
20
R2 = 0.163
15
10
5
0
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
Diagnostic Checks Results
ASSUMPTION TEST
RESULT
Linearity
Half-Slope Ratio
Violated
Homoscedascity
MSE ratio
Violated
Independence
Durbin-Watson
Not violated
Normality
Ryan-Joiner
Violated
Outliers
LMS Procedure
1995, 1998
Percent Warm Days (1958-1999)
Excluding 1995, 1998
30
Warm Days (%)
Y = -115 + 0.061X
25
P = 0.060
95%CI = {-0.003, 0.125}
20
R2 = 0.090
15
10
5
0
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
Conclusion #1

The claim of an increasing linear trend in
the percent of warm days in the
Caribbean during 1958 -1999 has no
valid statistical basis, is erroneous and
misleading.
Conclusion #2

Climate scientists must exercise greater
care in their statistical analyses to avoid
contributing to climate alarmism with
erroneous and misleading conclusions.