Green by Protocol

Most "green" blockchains either use little energy (proof-of-stake) or buy offsets with a foundation budget. Neither removes anything from the atmosphere, and both can stop tomorrow. NetZero Chain makes carbon removal a consensus rule: a block that does not credit the Carbon Fund is not a valid block.

The flow, step by step

 transaction fee (USDn)
        │
        ▼  every block, in the consensus engine
   ┌──────────────┬──────────────┬──────────────┐
   │ 50 %         │ 40 %         │ 10 %         │
   │ Carbon Fund  │ miner pool   │ proposer     │
   └──────┬───────┴──────────────┴──────────────┘
          │  timelocked withdrawal, purpose on-chain
          ▼
   60 % buy removals  ·  25 % CDRT liquidity  ·  15 % buy CDRT and burn
          │
          ▼
   credits moved into the Northern Trust Carbon Ecosystem vault
          │
          ▼
   CDRT minted 1 : 1 per tonne in the vault
          │
          ▼
   burn CDRT → the tonne is retired the same day

1. Fees are collected by the block, not by a contract

The coinbase of every block is the fee sink address. Base fee and tips of every transaction land there during execution. At the end of the block the engine takes the whole balance and credits:

Share	To
50%	Carbon Fund `0x…1001`
40%	Mining share pool, split equally over the block's shares; a block with no shares pays it to the proposer
10%	The validator seat that sealed the block

The fee sink is back to zero after every block. Any node verifying the block recomputes this; a proposer who keeps more than its share produces a state root nobody else accepts.

2. The Carbon Fund can only buy removals

On the mainnet design the Carbon Fund is a contract. Withdrawals go only to a whitelisted purchase address, after a 7-day timelock, with a record on-chain of the intended purchase: tonnes, supplier, vault account. Anyone can watch the queue. On the testnet the fund is a plain balance so the flow can be observed; the contract is on the roadmap.

The withdrawn amount is used as the business case specifies: 60% buys removals, 25% provides CDRT liquidity, 15% buys CDRT on the market and burns it, which retires tonnes permanently.

3. Removals, not offsets

The fund buys carbon dioxide removals: reforestation, biochar, enhanced weathering, direct air capture, blue carbon. Not avoidance credits, not renewable-energy certificates. Standards accepted are defined in a published Grouping Standard that an independent auditor has approved.

4. Custody at Northern Trust

Net Zero Company AB is a member of the Northern Trust Carbon Ecosystem under a CDRT agreement signed in January 2026. Credits sit in a dedicated vault account with daily volumetric reconciliation, quarterly retirement and delivery reconciliation, and read-only access for the auditor. This is the part every previous on-chain carbon token lacked.

5. CDRT: one token, one tonne

CDRT is an ERC-20 minted only after credits are in the vault; each mint event references the vault deposit. Burning CDRT emits a retirement request that must be fulfilled the same or next business day. Supply on-chain always equals tonnes in the vault, and a daily NAV publication makes that checkable. Details: CDRT.

What you can verify, and where

Claim	Verify by
50% of this block's fees went to the Carbon Fund	Sum `gasUsed × effectiveGasPrice` over the block's receipts; compare the Carbon Fund balance before and after. See Fee Accounting.
The fund only spends on removals	Timelock queue and purpose records in the Carbon Fund contract (mainnet design).
Tonnes in custody equal CDRT supply	NAV oracle contract daily; quarterly auditor reports published by the company.
A burn retired a tonne	Burn event on-chain; retirement in the vault reported by the auditor.

How much does it remove?

At an average fee of $0.05:

Transactions/day	Carbon Fund/day	Removals/year (60% at $25/t)
10,000	$250	~2,200 t
50,000	$1,250	~6,600 t
250,000	$6,250	~33,000 t
1,000,000	$25,000	~131,000 t

Ten validators plus a few hundred CPU miners emit in the order of 200–400 t/year. The chain is carbon-negative from one to two thousand transactions per day, and the ratio only improves with volume. The KPI page will publish tonnes removed against estimated tonnes emitted every quarter.

Why this is different from "we offset our footprint"

It cannot be turned off without a hard fork every node operator would have to knowingly adopt.
It scales with use, not with a marketing budget.
The money is not spent by a person deciding to be green; it is spent by a rule.
The removals are held by a $16 trillion custodian, not in a project wallet.