An Post said it has achieved a 50% reduction in carbon emissions three months ahead of schedule - one of the first national postal organisations in the world to reach this milestone.
An Post said the milestone marked a "rare example" of how a large semi-state commercial body could deliver measurable climate impact while simultaneously growing its business and profits.
An Post's original target of a 50% CO2 emissions reduction by 2030 was set in 2017, but in 2021, the company brought forward this target to the end of this year.
It said this reflected the urgency of delivering climate action and demonstrating its commitment to pursuing Ireland's sustainability goals.
Through a €100m investment to decarbonise its operation, more than half of An Post's delivery routes are now electrified by the country's largest electric vehicle fleet.
95% of its heavy vehicles have been switched to renewable HVO fuel, with 99% of its buildings now powered with green energy.
An Post said this 50% milestone has been achieved despite a 300% increase in parcels, from 20 million delivered in 2009 to 78 million this year - with 1.25 million extra parcels delivered each week.
David McRedmond, CEO at An Post, said the company is building a cleaner, more resilient logistics network for decades to come.
"Achieving the 50% reduction target early is proof of how serious our commitment is. As the operator of the largest fleet in Ireland, this has required a relentless approach to electrifying the fleet and using renewable fuels," the CEO said.
"It is a huge credit to the frontline staff in An Post, across every community, that while transforming to a parcel logistics business they have also achieved a world-class standard in sustainability," he stated.
David McRedmond said that halving the company's emissions is a huge step, but it is only part of the journey.
"The next task is to meet net zero by 2030. Achieving the first of our targets gives us renewed confidence that we will also achieve this goal on time with more EVs, renewable fuel and energy," he said.
Minister for Culture, Communications and Sport Patrick O'Donovan said that An Post is using its growing electric fleet to drive delivery of parcels, letters and transformative change in environmental sustainability on the path to net zero.
Owen Keogh, An Post Head of Sustainability, said there is currently one EV for every 2,700 people in Ireland, and An Post is ranked amongst the top five global postal companies for sustainability.
"Our experience with EVs has been exceptional with 50% fewer breakdowns and reduced mechanical interventions compared to diesel vehicles," Mr Keogh said.
"An Post expects to extend EV leases to up to seven years from 2026. This year alone, An Post EVs will travel 18 million kilometres emissions-free, keeping Ireland moving with cleaner air for communities", he added.
