“Teshuva, Tzedaka and Prayer, remove the bad parts of the decree.” (Unetane Tokef)
It was said of Rabbi Tarfon that he was very wealthy but did not give sufficient Tzedaka-money to the poor. Rabbi Akiva once found him and said, “My teacher, would you like me to purchase a city or two for you?” Rabbi Tarfon replied: “Yes.” He immediately gave him four thousand gold dinars.
Rabbi Akiva took the money and distributed it to the poor.
A while later, Rabbi Tarfon found him and said, “Where are the cities you purchased for me?” He took him by the hand and brought Rabbi Tarfon to the house of Torah study. He then took a Book of Psalms and placed it in front of them. They read and read, until they came to the verse, “If a person gives money to the poor, his acts of Tzedaka will stand him in good stead forever.” (Psalm 112:9)
Rabbi Akiva said, “This is the city I bought for you!”
Rabbi Tarfon arose and kissed him on the head and said, “My teacher! My hero! My teacher in wisdom! My hero in the essences of life!”
He then gave Rabbi Akiva more money to give away.
The Tzedaka that can help negate the worst part of the decree is Tzedaka that emulates the Creation we honor on Rosh Hashana: It must be life building.