The UK government’s environmental adviser has accused ministers of failing to plan for the “inevitable” impact of climate change, despite its repeated warnings, leaving the country worse prepared to tackle global warming than it was five years ago.

In its latest, quinquennial stock take of the climate risks facing the UK published on Wednesday, the Climate Change committee said the recent focus on reducing emissions had not been accompanied by adaptation planning, which had failed “to keep pace with the effects of a warming planet”.

Chris Stark, chief executive of the CCC, accused ministers of ignoring the independent panel’s recommendations. “We’ve been raising our concerns consistently for some time now. [The government has] found it far too easy to dismiss those,” he said.

“We need a better plan from government,” said Stark, adding that the group’s unusually critical tone was “designed to elicit a response”.

Environmental strategies must incorporate both emissions cuts and planning for “the changes in climate that we know we’re going to see”, he said.

The failure to plan for changes to the climate that were now unavoidable had left the UK in a worse state of preparedness than it was when the CCC’s last assessment was carried out in 2016, the report found.

“Further change in aspects of the UK’s climate is inevitable — no matter how global greenhouse gas emissions change in future,” it warned.

The damning assessment comes days after the climate commitments made at the G7 summit, hosted by UK prime minister Boris Johnson, were criticised by environmental groups for neglecting to detail plans to help the poorest nations cope with the effects of warming.

The summit was seen as a key test ahead of COP26, the climate conference that the UK will host in November.

The report will also raise questions about Johnson’s promise to put the environment at the heart of his administration. It catalogued 61 risks and opportunities, nearly 60 per cent of which were rated as urgently in need of attention, compared with a third in the 2016 assessment.

The analysis, which will inform the government’s own five yearly climate change risk assessment due next year, said the worsening state of preparedness reflected the pace of change outstripping the pace of adaptation.

The government had “not heeded the CCC’s advice on the importance of [an adaptation] plan or on funding it adequately”, it said, warning that even if global emissions fell dramatically in the coming years, the UK would continue to experience warming because of locked-in changes caused by historic emissions.

By 2050, the heatwave of 2018 — the hottest summer on record according to the UK’s Met Office — “will be a typical summer”, the report said, adding that average rainfall in the warmer months could drop by as much as a quarter. It said more than 570,000 homes built since 2016 were “not resilient” to future high temperatures.

It also identified an “urgent” need to assess the resilience of the country’s electricity grid, which will have to expand to cope with increased demand from “greener” technologies, including electric vehicles.

Other near-term priorities include gaining a better understanding of the damage climate change can cause to natural carbon stores, such as peatlands and forests, as well as its impact on crops and livestock.

“We cannot deliver net zero without adaptation,” said professor Dame Julia King, chair of the CCC’s adaptation committee. “It’s absolutely illogical that we are not doing it.”

Adaptation planning must factor in global warming of between 1.5C and 2C by 2100 at a minimum, and consider the risks of up to 4C of warming, the researchers said.

The government is expected to publish this year its road map for reaching net zero and an assessment of what the transition will cost. Stark said it was “a failing” that the Treasury’s assessment did not consider the cost of adaptation.

The government said it would consider the report’s recommendations “closely.”