"The Lord smelled the pleasing aroma and said in his heart: 'Never again will I curse the ground because of man, even though every inclination of his heart is evil from childhood. And never again will I destroy all living creatures, as I have done.'" NIV translation
God's promise is that this judgment is never to be repeated. You have probably heard the saying "he has a good heart" in reference to a person but, as we see here, we all have a heart of sin. Even so, God said that He would not judge the earth again in this manner.
"'As long as the earth endures, seedtime and harvest, cold and heat, summer and winter, day and night will never cease.'" NIV translation
There will be no more judgments until the final day which is known as the Day of the Lord.