Since you agree "that the earth has warmed since 1850 and that human activity can change the climate", it looks like our differences are about how bad it's going to be.
Like you, I don't believe the more alarmist claims.
But, unlike you, I believe that there are some very real consequences from this human caused warming. Like my ruined vineyard, which is due to overly mild winters, starting about 10 years ago.