use funds made available to the Secretary and not otherwise obligated to carry out the purposes of this section. 302. Promotion (a) In general The Secretary shall promote the purchase of climate change obligations through such means as are determined appropriate by the Secretary, with the amount expended for such promotion not to exceed $10,000,000 for any fiscal year during the period of fiscal years 2024 through 2028. (b) Donated advertising In addition to any advertising paid for with funds made available under subsection (c), the Secretary shall solicit and may accept the donation of advertising relating to the sale of climate change obligations. (c) Authorization of appropriations For each fiscal year during the period of fiscal years 2024 through 2028, there is authorized to be appropriated $10,000,000 to carry out the purposes of this section.