Mary Robinson has said coronavirus has made her optimistic that we can tackle climate change.
Ms Robinson, who is chair of The Elders, an independent group of global leaders working together for peace, justice and human rights and UN Human Rights Commissioner, said that 2020 was set to be a significant year for global climate action, but the disruption caused by Covid-19 has shown the possibility for a global change in how we treat our environment.
"At first it might seem as though there is no hope of achieving the kind of climate action needed," the former president wrote in an article for Sky News.
"Yet, the pandemic has also shown that the international community can come together when the need arises. It has demonstrated that it is possible for human behaviour to change at pace on a global scale.
"While COVID-19 has intensified prevailing inequalities, these issues are all parallel to those with which we must grapple to overcome the climate crisis too."
Ireland became the second country in the world to declare a national climate and biodiversity emergency just over a year ago, but the country was still ranked the second-worst in the EU in relation to climate.
Ms Robinson said that she was dejected at the beginning of 2020, that "we lacked any sign of the kind of leadership needed to meet the climate commitments".
She has been encouraged by the response to the coronavirus by ordinary people, however, and by leaders who took decisive action, like those of Germany, Norway, Denmark, Finland, Iceland, New Zealand and Taiwan.
The first female president of Ireland did say that the pandemic has highlighted leaders who did not respond well to the crisis.
"The pandemic has shown us how crucial international collaboration is to tackle global crises, it has also exemplified the inextricable links between public health and planetary health," she wrote.
"Health professionals and scientists are telling us that health systems are not resilient enough to cope with the existential threat of the climate emergency.
"Some individual country responses to the Covid pandemic have also demonstrated the dangers of sidelining the science - it has given us a glimpse of the human cost.
"Scientific convergence of opinion on what is needed to fight climate change is so strong that any failure to urgently act now, even in the face of other crises, would be a grave injustice to our children and future generations."
"Now is the time to act," she concluded.