I just don't want to see the earth hit by a large meteor like the one that wiped out the dinosaurs. Now that is almost instant climate change! Also I do not want to live to experience the next ice age.
"At the moment the Earth is in an interglacial period - a short warmer period between glacial (or ice age) periods.
The Earth has been alternating between long ice ages and shorter interglacial periods for around 2.6 million years.
For the last million years or so these have been happening roughly every 100,000 years - around 90,000 years of ice age followed by a roughly 10,000 year interglacial warm period."
From:
What causes an ice age and what would happen if the Earth endured another one? - ABC News