The report came as world leaders gathered in this Polish city for the annual UN climate negotiations (COP24).
Low and middle-income countries have shown consistent progress in bridging the gap in adaptive capacity, it said.
The research particularly underscores a growing divide between the estimated annual costs of adaptation and the actual global investments in resilience measures, drawing a distinct connection between our adaptation to climate change and sustainable development that results in healthy communities and thriving economies, according to the UN.
Climate change will have a significant impact on human health over the next few decades, and while progress has been made in reducing climate-change related diseases and injuries, current adaptation efforts are by no means sufficient to minimize future health impact of a changing climate, it said.
The study highlighted that unless adaptation efforts were strengthened considerably, heat and extreme event-related morbidity and mortality will continue to rise.
Despite voicing considerable concern on the divergence between the global goals on adaptation and actual action being taken at the national level, the report shined a positive light on the growth in national laws and policies that address adaptation.
Studies show that at least 162 countries explicitly address adaptation at a national level, through a total of 110 laws and 330 policies.
Looking at the commitment countries made as part of the Paris Agreement, only 40 developing countries have quantifiable adaptation targets in their current Nationally Determined Contributions (NDCs), while 49 include quantifiable targets in their national laws and policies, according to the report.
The study said that low and middle-income countries showed consistent progress. But it added that without signs of acceleration, catching up with wealthier countries to bridge the gap in adaptive capacity will take many decades under current rates of improvement.
According to the report, political will, necessary financial resources to implement important actions related to climate resilient health systems, early warning systems and a broader development agenda aimed at reducing vulnerability to climate-sensitive health risks were needed to narrow the adaptation gap in health.