By Pablo UchoaBBC .css-14iz86j-BoldText{font-weight:bold;}From rock art in southern Africa to pyramids along the River Nile, humans have been leaving their mark across the continent for millennia. .css-yidnqd-InlineLink:link{color:#3F3F42;}.css-yidnqd-InlineLink:visited{color:#696969;}.css-yidnqd-InlineLink:link,.css-yidnqd-InlineLink:visited{font-weight:bolder;border-bottom:1px solid #BABABA;-webkit-text-decoration:none;text-decoration:none;}.css-yidnqd-InlineLink:link:hover,.css-yidnqd-InlineLink:visited:hover,.css-yidnqd-InlineLink:link:focus,.css-yidnqd-InlineLink:visited:focus{border-bottom-color:currentcolor;border-bottom-width:2px;color:#B80000;}@supports (text-underline-offset:0.25em){.css-yidnqd-InlineLink:link,.css-yidnqd-InlineLink:visited{border-bottom:none;-webkit-text-decoration:underline #BABABA;text-decoration:underline #BABABA;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-skip-ink:none;text-decoration-skip-ink:none;text-underline-offset:0.25em;}.css-yidnqd-InlineLink:link:hover,.css-yidnqd-InlineLink:visited:hover,.css-yidnqd-InlineLink:link:focus,.css-yidnqd-InlineLink:visited:focus{-webkit-text-decoration-color:currentcolor;text-decoration-color:currentcolor;-webkit-text-decoration-thickness:2px;text-decoration-thickness:2px;color:#B80000;}}But extreme weather events, the rise in sea levels and other challenges associated with the changing climate are threatening to destroy invaluable cultural landmarks,…