If you had the sense that Paul Ehrlich and Garrett Hardin are very much figures of the 1970s nexus of environmentalism and population control, it seems you are right. According to Google Ngrams mention of these topics has been declining since peaking during the oil crisis, in the afterglow of the influence of the late 1960s counter-culture. The general social survey has a variable, POPGRWTH, which asks:
And please circle one number for each of these statements to show how much you agree or disagree with it. The earth cannot continue to support population growth at its present rate.
The question was asked in the year 2000 and 2010. Demographic breakdowns below for the pooled responses….
Earth can not sustain population growth
Strongly agree
Agree
Neither
Disagree
Strongly disagree
Non-Hispanic white
15
41
22
20
3
Non-Hispanic black
6
32
28
29
5
Hispanic
14
39
22
23
3
Male
14
42
18
22
4
Female
13
38
26
21
3
Highest educational attainment
< HS
14
46
18
19
3
HS
13
38
24
22
3
Junior College
11
37
28
23
2
Bachelor
14
41
20
21
4
Graduate
16
40
17
23
5
Intelligence, measured by vocab score (WORDSUM 0-4 = stupid, 5-8 = average, 9-10 = smart)
Stupid
14
38
23
21
4
Average
12
41
23
22
3
Smart
21
37
15
22
5
Liberal
20
43
19
17
1
Moderate
12
41
27
18
1
Conservative
11
36
19
28
6
Protestant
12
39
22
23
3
Catholic
13
39
24
21
4
Jewish
15
33
22
30
0
No Religion
18
47
20
13
2
Bible is….
Word of God
11
35
23
27
5
Inspired Word of God
11
41
25
21
3
Book of Fables
23
43
14
18
2
Opinion as to the existence of God
Don’t believe
35
34
13
15
3
No way to find out
24
39
22
14
1
Some higher power
21
51
11
17
1
Believe sometimes
18
43
23
16
0
Believe but with doubts
13
44
22
19
2
Know God exists
11
37
24
24
4